If you have read through these forums recently or looked at any posts relating to Power Pack 1, then you will hopefully know by now that Vista 64 bit support will be included in Power Pack 1 which is about to go into public beta.
If you want to sign up for the beta go to Connect.microsoft.com and sign up.
Please be aware though that the whole point of the public PP1 beta is to test the data corruption fix and not for people to just test 64 bit support.
Andrew