Well, on my second go-around I'm loving the control you now have over the document tabs. Three things in particular: vertical tabs, alphabetically sorted tabs, pinned tabs and regex colored tabs... ok, that was four things.
In the past I used to have to put up with VS2010 being able to show about 5 or 6 open documents via the tabs (I run duel 22 inch LCDs at some weird-ass resolution), anything else and I'd have to go to the annoying little drop down arrow. But check out this screenshot of my current layout with vertical tabs, not sure how many tabs I could get in there but it'd easily be 30-odd and they'd all be easily readable.
Using the regex colored tabs means each different file type has a different color plus I've set parent/child documents to be different shades of the same color (see the aspx and aspx.cs files and the ascx and ascx.cs files?). It ain't pretty but man can I find the file I'm after quick smart!
Having the tabs sorted alphabetically means related documents are stacked on top of each other, again making things easier to get at.
Lastly, pinning tabs means frequently accessed files are always in the same spot. I have my web.config and default.css within easy reach. No more hunting around in the Solution Explorer. Yay!
Here are my settings (click for full res):
