Bethseda has said all along they want to release PC and Xbox versions at the same time. They haven't said much outside of the info in the FAQ, but the devs have chimed in on a few issues that I thought were important. Since this stuff was actually said by bethseda officials and not one of the plethora of morons that just plain make stuff up (mostly xbox360/PC rivalry kind of stuff) over on the forums, it can be reasonably assumed its true.
1) It will NOT use starforce.
2) Windows 2000 is in testing. At the very least, they aren't going to try to roadblock you trying to install it on 2K. They just may not officially support it. The likely will after testing, since its pretty unlikely they will encounter any 2K only problems.
Also, there had been some mutterings from a PC gaming mag (UK I think) running a preview of it. They said it ran like a dream at 1280x1024/High on a robust A64 (can't remember exact model) 1GB of ram and a 7800GT. A 7800GT is a pretty beefy card indeed, but it does indicate that will probably won't have another repeat of morrowind where top of the line hardware runs it like crap.
I'm a bit more optimistic about performance after hearing a few of these things. I'll wait until a few reviews and some benchmarks come out before buying it. I'm probably going to snag new video card right after it comes out, I figure the longer I wait the cheaper/better performance I can get out of my video card buy. I'll move my 6800NU over to my wife's PC at that time. I'm hoping that will actually run well since it meets the recommended specs (barely).