While I too run as admin on my machines at work and home, the VS team does put a lot of work into making sure that you can use our product as a normal user on the machine. I've seen many a bug about issues from arising from running with a less than admin
account (worked on one today in fact).
Most dev's like to be admins on their machines anyway to run things like gacutil, regsrv32, etc. but we do try to make it possible!