Your proccessor does support 64 bit and while software is backward compatible, drivers are not. Read this extract and then decide.
From -
http://blogs.zdnet.com/Ou/?p=440&page=2
While these are the fundamental hardware drivers you'll need, the killer for Vista x64 edition is finding drivers for obscure hardware like cameras, printers, scanners, and other accessories.
You don't have to worry about 32 bit software compatibility in Windows Vista or XP x64, since they run natively and seamlessly, but drivers are an absolute killer. If you happen to find 32 bit drivers for your device but no 64 bit drivers, you're out of luck if you're running x64 Windows XP or Vista. For this reason, x64 edition for a typical consumer is usually not very practical because there are simply too many hardware peripherals you won't be able to use. Getting the computer itself to work is relatively easy; it's the one or two obscure devices that stops you dead in your tracks if you must have that device working. For this reason, no PC maker (that I'm aware of) will pre-load x64 edition of Windows on its PC because it will be a support nightmare if a customer starts complaining about a printer driver that won't load. To this date, Apple iTunes won't support any x64 edition of Windows, and it will absolutely not work at all because of hardware driver issues.
