rkeslar,
Your version number is correct. It was 3.5.0.0 in pre-sp1 as well as after sp1. (I'm confused about this too, but it certainly is nice not to have to upgrade all of our config files).
The only weirdness I found in the non-version change is that some of the sp1 features used to be in the ASP.NET Extensions December CTP, where the version number was 3.6.0.0 -- so if you were using any of those features, the version has actually regressed.
I think you are good to go.
James