A new Chip-8 emulator by 00Laboratories is out now and it is called 00SChip8.
Here's a word from one of the author's Henry 00:

From nGlide:

NES Emulator for Windows has been updated

• Fixed SlimDX Audio frequency control.
  
• SlimDX Video mode improved to be faster.
  
• Added mapper # 185, 187, 188, 189, 226, 228, 229, 230, 231, 232, 233, 240, 241, 242, 243, 244, 245, 246, 248, 249 and 251
  

From AHD:

Forum member Mike Chambers has informed us an emulator he has recently re-worked on and completed in C when it was originally worked on in Basic and abandoned.

It's open-source, supports all 8086 and 80186 instrutions, emulates most of the standard PC hardware, uses image files for floppy/hard drive (like QEMU), runs on windows/linux (and OS X with a little tweaking of the source)..

It runs every version of DOS.

feature overview:
-complete 8086/80186 CPU emulation
-intel 8259 interrupt controler emulation
-hercules/CGA/MCGA/VGA emulation (lacks EGA and 640x480 4-bit VGA currently)
-adlib emulation
-disney sound source emulation
-in windows, it can use winpcap to emulate a network card... theres a special DOS packet driver designed for it that is on the fd-fake86.ima floppy image that comes with the windows download (PD.COM)

(no DMA controller or sound blaster emulation yet, but eventually...)

more info, downloads, screenshots, etc:
http://fake86.rubbermallet.org

video of it playing Wolfenstein 3D:
http://www.youtube.com/watch?v=GIgcIgz-EQ4

^youtube's encoding messed up the audio pretty nicely for some reason. it sounds better than this. the video there sounds like its underwater or something.

it's also very fast, it rivals DOSBox for speed. depending on what's being emulated, it'll emulate between 25 million and 70 million instructions/sec on my 3.2 GHz AMD Phenom II X4 955.

Download the emulator on Zophar's Domain here.

In case you missed the news post last month, FCEUX had gotten updated and here were the changes.

• Completely overhauled GTK2 GUI: new options, revamped dialogs, and more.
  
• Improved compatibility.
  
• Movie performance increases.
  
• New lua functions.
  
• GTK_LITE build option depreciated in favor of \"--nogui 1\".
  
• Improved sound support for SDL.
  
• Win32 - Debugger - Fixed some crashes and make RAM search only display valid addresses.
  
• Win32 - Fixed some minor GUI issues.
  
• Win32 - TASEdit - Overall cleanup; fixed crash when truncating while turbo is enabled
  

Nes emulator for Nintendo DS updated.

What's new:

• Big nose freak out update.
  
• mapper225 226 227 229 230 231 255 added.
  
• Sound enhanced.
  
• Raw PCM update, nearly perfect.
  
• sprite0y update.
  
• nifi update.
  

The NES emulator for Nintendo DS has been updated:

What's new:

• Mapper1 updated.
  
• Auto-fire adjusting added.
  
• Swap-Screens disabled if LIGHTGUN active.
  
• sprite0y for SP-pertile fixed.
  
• Careful to use Swap-Screens, which may shutdown DS.
  

The Vectrex emulator for the Nintendo Wii has been updated.

What's new:

• There's plenty of visual upgrades/customisations on this version.
  

The Atari 5200 emulator for Nintendo DS has been updated.

What's new:

• Fix bug in GTIA/POKEY for enabling pot management, analog jostick works now;
  
• Compiled with new devkitpro (r33), win 1 fps since previous version.
  

PCSX-Reloaded is a fork of PCSX for Windows, Mac OS X, and Linux that has been around for some time and has been noted at this site in the description for PCSX, but until now did not have its own page. This has now been fixed.

1.9.92 was actually released some time ago from what I can see, but here's the latest whatsnew regardless:

• Many fixes/changes to the core and Internal HLE BIOS.
  
• Root counters code has been rewritten.
  
• Use GTE code from PCSX-Revolution Project which improved accuracy.
  
• Added netplay plugin for *NIX (based on netSock).
  
• Native support for FreeBSD and Solaris.
  
• Replaced HIDInput and CDDeviceInterface plugins with dfinput/dfcdrom for Mac OS X.
  
• PPF patching support.
  
• Other minor bugfixes/tweaks.
  

After 10 long years, the Jagulator has returned with a new update for Jaguar fans to ejagulate to. It is an Atari Jaguar emulator for Windows/PC and it has new core and GUI.

Download the emulator here or at http://www.jagulator.com/

gbpablog is another Game Boy emulator we didn't have on this site until now. It's written in C++, using WxWidgets and SDL. Little information seems available on the actual features, but savestate and sound support are mentioned in the latest changelog, and the screenshots show gameplay of commercial games, so I presume compatibility is at least half-decent. However, only classic Game Boy games are shown, so I don't think this emulator has GBC support as of yet.

Binaries are available for Windows, Mac OS X, and Linux, but the source code is only available via a Mercurial repository.

The current version is 0.9, and here's what's new in that version:

• Added sound
  
• Added support for savestates
  
• Improved the way the frames are drawn
  
• Fixed bug in MBC
  
• Implemented serial port interruption (needed by some games)
  
• The SDL library is no more needed to be installed in MacOSX, is included in the app bundle
  
• Improved accuracy
  
• Improved compatibility
  

• Choppy sound with the package libsdl1.2debian-pulseaudio.
  
• Delayed sound with the package libsdl1.2debian-alsa but with some games can be acceptable.
  
• The emulator hangs with the package libsdl1.2debian-esd.
  

CrystalBoy is a Game Boy emulator for Windows written in C# that has evaded our attention until now. It has high compatibility, emulates both the classic Game Boy and Game Boy Color, and has a graphical debugger. However, it's still missing sound and has some remaining compatibility issues.

The current version is 1.3 but the downloads page for the emulator only has source code for the initial release. Fortunately, it seems the latest source code is available via a Subversion repository. The changes for 1.3 are as follows:

• More accurate CPU emulation (according to the tests, all instructions now compute 100% exact… Only HALT and STOP may need reworking)
  
• Direct2D render method with SlimDX (March 2011)
  
• More accurate graphics emulation (dynamic color palette changes, correct sprite priority emulation)
  
• \"Perfect\" RTC emulation
  
• Bugfixes in Mapper emulation (generic mapper bugfixes and some MBCx specific ones)
  
• Enhanced various areas dealing with game information
  
• Added support for saving the RAM for games with battery (finally !)
  
• Saving the RAM also saves the RTC information for games using the RTC
  
• UI is now localizable
  
• Added fr-FR localization
  
• Better detection of invalid plugins, which should prevent crashes.
  
• Hardware Type can now be changed using UI (Menu items previously did nothing…)
  
• Various chanegs in emulation for hardware type switching. (Quite logically, changing hardware now requires the emulation to be reset)
  

BGB, a rather high quality Game Boy emulator for Windows, has been updated to version 1.3.2. Here's what's new:

• more accurate SGB color scheme.
  
• improved detection of non-working vsync.
  
• fixed: bootroms don't load if read only.
  
• fixed: \"load rom dialog on startup\" not working.
  
• fixed: \"game controller works only if focus\" not working.
  
• fixed: setting borderless window, and switching to fullscreen, if using directdraw, the \"window\" can still move, and cause graphical glitches and crash.
  
• fixed: GBC accurate initial WRAM values as left by bootrom (fixes the menu in baby felix - halloween).
  
• fixed: a sprite on X = 0 uses more time in mode 3, too.
  
• fixed: inconsistent timing if resetting in the debugger.