Am I taking a big step with this upgrade?

Current Rig:

X1600 Graphics Card AGP Slot
1gb DDR RAM
2x3.4ghz Core Duo
Regular Monitor
Windows XP

Desired Rig:

8800GTS 320MB PCI-e Slot
2GB DDR2 RAM (I have another mobo which supports both the DDR2 and the PCIe)
Same Processor
Same monitor
Possibly Vista - or may stick with XP

What I want to know is if Im taking a large enough step up. Monitors/resolution doesnt matter much to me, 1024x768 on a standard monitor seems gd to me, just how high I can pump up the settings without nuking my framerate.
Any suggestions? Advice?

Current Rig:

X1600 Graphics Card AGP Slot
1gb DDR RAM
2x3.4ghz Core Duo
Regular Monitor
Windows XP

Desired Rig:

8800GTS 320MB PCI-e Slot
2GB DDR2 RAM (I have another mobo which supports both the DDR2 and the PCIe)
Same Processor
Same monitor
Possibly Vista - or may stick with XP

What I want to know is if Im taking a large enough step up. Monitors/resolution doesnt matter much to me, 1024x768 on a standard monitor seems gd to me, just how high I can pump up the settings without nuking my framerate.
Any suggestions? Advice?

F4ll3n_1

The RAM alone will make a HUGE difference. The Graphics Card is also great, though if youw anted to you could get an 8800 GTX and overclock it(to par it iwth an 8800 Ultra), or just wait for the 8900s to come out later this year. For the processor, Core 2 Duo might be a good idea, though it's not necessary. As for the monitor, You might want to get a monitor that can do the max resolution of your graphics card unless you already have a good monitor, for it to look the best. You probably want to get Vista. The 2GB RAM should easily handle Vista, and you can also run DX 10 and games for Vista if you want to.