Quirky! I just noticed that Microsoft ended up extending the support lifecycle for Exchange Server 5.5 to 10th January 2006 instead of ending it as planned on 31st December 2005. This was done to align the end of support life timings will the release of our Monthly Security Bulletin on the second Tuesday of each month. So there I was crying into my champagne at midnight on 31st December when Exchange 5.5 was actually still alive, albeit barely...

Read all about it here: http://www.microsoft.com/presspass/features/2006/jan06/01-10Support.mspx