Thanks for the feedback. We are changing the warning message in VS 2005 SP1 RTM. It will "recommend" users to run with administrator privileges, inform that some scenarios will need admin privileges and will also contain a link to information on which scenarios/features
need admin privileges.
Most of issues with running VS 2005 on Vista as standard user (for example, COM registration fails) exist when VS 2005 is run as normal user on XP.
We will be publishing the list of known compat issues when VS 2005 is run on Vista (along with workarounds where available) to MSDN in next few days. We are working on publishing a similar list for VS 2003 within the next few weeks.