Well...I use this laptop as a desktop replacement for now because it's configuration (Core 2 Duo T7300 2.0GHz, 2GB DDR2, 256MB Video nVidia 8400GT, Blu-Ray Writer) is for multimedia use, so I watch HD movies on it, I play all the new games at reasonable quality and I can't say that I REALLY need x64 because I use common aplications but I don't really like x86 Vista because it's slower and more at risk to malware than it's 64bits brother.
So this are the main reasons for wanting x64 drivers, some of them are on the VAIO Support Home-Page but the rest aren't...
Hyper