I've been using Vegas Pro in 64-bit ever since i moved to an x64 based system (windows 7 beta and now professional), but can't tell if it speeds anything up that is processor based. Obviously, it's able to address more memory (i'm currently at 4gb in my 2.0ghz santa rosa core 2 duo), but does the ability to send the processor larger chunks of data to chew on make a difference in rendering or playback?