The smart guys over at Developer Division have been working on making Visual Studio perform better. A key need they have in achieving this is for real data - actual metrics on where Visual Studio is running slow for real users.
To this end, they’ve released a new Visual Studio Add-in, Visual Studio Perf Watson. Go read the announcement on the Developer Division Performance Engineering blog and then, if you are experiencing any slowdowns, go install PerWatson.
Unfortunately, not for XP. I’d install this at work in a heartbeat if it was supported.