For you date watchers out there, today (October 22, 2009) marks the day that both Windows 7 and Windows Server 2008 R2 hit the retail streets.  Of course, the bits have been available on MSDN and to Enterprise Agreement customers for quite a while now.

Lots of goodness on both fronts.  Personally, I've been using Windows 7 now for about 6 months and I've never looked back [to XP/Vista].  The two best features are Libraries and XP Mode.  I highly recommend it!

Windows Server 2008 R2's biggest splash (from my edge of the world) is Hyper-V, plus some other gems like DirectAccess and RDS advancements.  Microsoft has a free eBook available for download here .  It's no slouch either, at 200 pages. Who doesn't love free?