Today I upgraded http://blogs.sqlxml.org to Community Server 2008. Previously it was running Community Server 2.1, so since I missed a few versions the upgrade was not quite as simple as it could have been. However, it went pretty well overall I think. Let me know if you find anything that is broken.
Right now I think the only thing that I know is broken is my Silverlight add-in, which I will fix as soon as I have some time to dig into how to upgrade that. I also haven't figure out how to get the Google ads on my personal blog. Not sure where those ads go now and the new documentation is pretty difficult to navigate.
Update: That was easy. Just fixed my Silverlight add-in by updating the referenced DLLs to the new 2008 DLLs and recompiled. Works!