I spent a couple of weeks in February hammering out a VS 2010 article for MSDN magazine. I tried to pick a collection of new things in the tool and/or runtime that would help developers be more productive. The article is here.
http://msdn.microsoft.com/en-us/magazine/ee336135.aspx (if you are reading as text only).
Clearly I didn't hit on everything, so feel free to mercilessly blast me if you think I grabbed the wrong items. It was frustrating trying to decide which ones should go in and which ones shouldn't. Keep in mind, the ultimate pivot for me was around productivity, not necessarily flashiness/performance or that kind of thing.