I installed 3.4.9 today, just on a lark. Everything seems to have ported over fine, except for one thing: the sidebar now renders all of the widgets in one big space, instead of giving them their own spaces, and does not recognize the CSS inserts I'd added to put custom images above and below each widget. Of course, going back to 3.4.6 fixes all of it.
Just curious...did how widgets get rendered change significantly between 3.4.6 and 3.4.9, or is this a small setting I neglected to tweak?