Visual Studio 2005 has the terrible habit of opening the full msdn library whenever you press F1, which in my case is mostly accidental. Not that I don't need help, but the F1 is a reflex I use when I don't understand the meaning of an option on the UI. I couldn't care less for msdn at that point.
Visual Studio 2008 seems to have a faster <cough> <cough> documentation explorer, but goes into what I'd consider to be pure vice: The little question mark box next to the close button is for bloody contextual help. Guess what, opening your big document explorer in my face when I'm already trying to understand what in the name of god you meant by allow checked-in items to be edited is not contextual. I loose my patience, and definitely loose my respect for whichever manager decided that after all, contextual help could be in the big documentation.
Can I have my tooltips back? Please?