Actually a few days ago, but I haven’t had much time to play with it yet.
Found a few issues with the x64 version with my accounting package (Small Business Accounting 2009 – which will be changing since MS has killed the product line) so you definitely want to test before you install in a production environment.
Microsoft recommends installing the 32 bit version in most cases, but suggests the 64 bit version for developers and those power users that have huge spreadsheets. Overall I’m very impressed, I expected to see a few conflicts; more than I did really. I have both 32 and 64 bit code running in slightly different environments, and both do very well. Outlook x64 can open huge PST files without complaining (my test file is now 12.4GB) assuming the machine has enough physical resources.
Haven’t played with everything yet, but definitely have a 4 up postcard mail merge printout in my future, if it still works the church will be very happy.