Skyrim is being developed to be able to run on a xbox 360. Really ANY computer less than 3 years old will be able to run Skyrim just fine. People seem to forget that the 360 is now over 5 years old. PC system requirements isn't really something to worry about until the next generation of consoles get released. Then you might have to consider it for a year or two while games scramble to take advantage of all the new power.
This.
Last I heard, the game is going to pretty much look the same on all platforms, which means that it's going to be limited by the Xbox 360, which has the weakest hardware of the consoles. So something like 4GB DDR2, a 256MB GPU, and a dual core CPU are going to probably be the minimum specs. Recommended I'd assume something like 4GB DDR2/3, 512MB GPU and a quad core CPU. That's assuming that it's going to be the same as the Xbox version, which generally have lower res textures and stuff.
So, yeah, your machine is okay. I'd look into upgrading your CPU and GPU, though. If you're on a budget, I'd bet an ATI 5770 would do just fine for graphics, and AMD processors tend to go fairly cheap. An AMD Phenom II is what I'd shoot for if I were you.