1 Gig RAM dedicated video cards have been around for a while now, and for mine I paid about US$100 or so IIRC back last autumn.
I'm fairly certain I have a 1 Gig video card (ATI Radeon HD 4800 series, can't remember which number, probably 4850 or 4870), which I bought around last september as well. I'm slightly annoyed that I bought it just before ATI released their first 5000 series graphics cards. I'm considering updating in the late summer/fall this year
I'd agree with the more recent posts that it'll probably run with 500 megs of video card RAM, as long as the graphics card has PS 2.0 or higher (as has been stated as an important requirement for Clausewitz engine games time and again). More is recommended for speed and fluidity.
I'd like to ask the devs how much, if any, attention is being paid to optimisation for multicore processors?
At least dual core is becoming quite standard, but a lot of games don't take advantage of the fact that much, and only run on one core, leaving the others idle (well, Windows and various background programs likely employ the other cores a bit, but still). For example, CK (which was released before multicores were in use in consumer hardware) runs surprisingly slow on my quad-core (not helped by the fact that I tend to have the PC on power-saving mode when playing it, which restricts the GPU and/or CPU).