It's about time! Microsoft should just stop making 32-bit OS's to force the issue. They have caused an incredible amount of confusion and uncertainty in the marketplace. It's nice to see Adobe take Sony's lead and start supporting 64-bit. Maybe now we'll have more 64-bit plug-ins for Vegas Pro. This is a step in the right direction.
The problem I see is there's still a lot of 32bit only apps and plugins that'll probably never get ported to 32bit. All the vendors who support AE and Ppro are hard at it of course but a lot of Vegas users rely on freeware that'll most likely never be updated. I guess we also need to think about the audio side as well, that could be a bigger can of worms.