Building a computer? Need advice/suggestions? Come here!

[Teroh]

Since my thread got closed: Thanks Con >:U

I'm currently in Italy, but when I get back home I'm thinking about upgrading my system at some point.
Specs you can see in my page but: (Note: This is my CURRENT computer.)

CPU: Intel E6600 C2D (2x2.4GHz)
RAM: Corsair 2x1 GB
Graphics Card: eVGA Nvidia 8800 GTS 640 MB
Mobo: eVGA 650i
PSU: generic 500W
Running Vista 32 bit.

Is it time for an upgrade? If so, what should I upgrade? Should I wait for the Nvidia 300 series cards to come out so prices on graphics cards drop? Should I upgrade to 64 bit? Should I upgrade to Windows 7?

Looking for suggestions and opinions here, I haven't made up my mind. Money isn't too much of an issue here, but let's keep it within reach.