I've been bothered this semester by the changes to the right-hand rich content sidebar, which in my mind have real problems from a usability perspective.
Firstly, the font got huge, which isn't necessarily bad in and of itself, except that it is a BIG jump in size, and means that if you have a long list of announcements or pages that have long titles, it just isn't easy to read.
Plus--and this leads into my second complaint--when you scroll down a long list in the sidebar, it no longer has its own scrollbar. That is, if you open, say, Announcements, it used to drop down in a little box that had a scrollbar of its own, so you could navigate the rest of the list WITHOUT having to scroll all the way down the main browser window. But now, if I'm editing a page and want to insert something from the sidebar, I'm constantly scrolling way down past the open editing window. I don't know if I'm explaining it well, but usability-wise it was a lot better to be able to see the rich content editor and sidebar at the same time. That way I was able to actually SEE the insertion as it happened.
Okay, </end rant>.