I just downloaded and installed Visual Studio 2010 beta 2 and started playing with it. As always, there are the occasional problems, especially when it comes to migrating projects.
On initially downloading and installing VS 2010 Premium (using the web installer), I received a generic error message at the every end of the install process, stating that there was a problem with the install. But VS 2010 seemed to be working properly so I ignored it.
Then, after playing with it for a bit, it was clear that intellisense was not working. Hit the period and nothing. No mouseover hints either. So, I reinstalled. Still nothing.
I was using a Vibrant Ink theme with VS 208 and this was picked up by VS 2010. While messing around trying to fix the intellisense problem, I rolled this back to the default theme and this fixed the problem. I was then able to reinstall the Vibrant Ink theme and get that working again.
Second issue was with migrating a MVC 1.0 project to MVC 2.0 and from VS 2008 to VS 2010. I tried this manually and it was a disaster. After lots of fooling around and tweaking I had to roll it back. I figured I was going to have to spend a couple days on this but, I found this nice little app from Elion Lipton and I had it up and running in 5 minutes. A nice save.
One other annoyance is the intellisense in web.config not picking up the IIS 7 rewrite module's markup. I tried this script file which may have worked for VS 2008 (the output window says it is updating VS 9.0) but did not work for VS 2010.
More notes as they arise.
UPDATE: This was the souce of the error message I received when installing and the solution.