Upgrading videocard; what can my system handle?

[Shadowtech]

I'm looking into upgrading the videocard for my desktop PC, but I'm curious just how "new" I can go that my system will actually be able to handle. In other words, could I upgrade to something like the nVidia GeForce GTX 400 series, or only the 200 series? Or something else entirely?

My current specs:

Power Supply: 650 watts
Processor: Intel Core 2 Duo E6750 @ 2.66GHz
Memory: 2GB System RAM
Hard Drive: 250GB
Video Card: GeForce 9600 GT
Operating System: Windows XP Home SP3
Motherboard: ASUS P5N-E SLI

So, given that... what do you think my system could handle for a new videocard?

[Linux711]

The minimum recommended system power for a GTX 480 is 600 Watts, so yes, you should be able to handle the 400 series.

[Computer_Commando]

The manufacturer of the card will specify the power requirements.  nVidia does not make the card, they make the graphics chip (GPU).