After using it for a couple of hours it looks stable and ready for use. Needless to say, it's nice to have it back in VS 2005 since the out-of-the-box refactoring support freezes the IDE 1/2 the time and takes at least a minute to complete the other 1/2 of the time. (I can finally get rid of all those extra C# using statements just taking up space!)
When you install ReSharper 2.0, it forces you to install to VS 2005 hotfixes. I'm not sure what happened after installing these hotfixes, but my ASP.NET solution compile times have gone from 1-2 minutes down to 10 seconds or so. Whatever the cause, needless to say, I'm happy with the results.
You can download the beta at http://www.jetbrains.com/resharper/beta20.html.