Yeah, Half Life 2 really could be a 'system hog', but it should run pretty good on my comp, at the least. Someone I know online tells me that the game will be able to run on a 700 MHz computer with a Pentium 3 with an Nvidia TNT 2. Yeah, like he says, it will look like crap, but you can run it on a system like that, just very stripped down. I'm pretty confident that a system like mine, with a GF 4 Ti4600 and 1 GB of RAM, could run HL 2 pretty good. Again, here's hoping!
Also, I have another question about RAM. Do you have to run with the same RAM, or have computer companies made it possible to run with two types of RAM (like a 2100 stick and a 3200 stick). My hunch is you need the same type, but I'd like to know what the real deal is.