I wish they'd let the old sidebar display as a third column if the viewport's wide enough. However, this:

> I'd stil like the language selector below the table of contents in the sidebar.

would also cover most of the reason I wish they'd do that.

[EDIT] Incidentally, what ever happened to 3-column layouts? They could keep the site menu on the left and stick the TOC on the right (keeping it visible all the time is definitely an improvement, and the thing I like most about this redesign). We used those layouts a ton when 800x600 4:3 was still a common monitor resolution & ratio, so surely it'd be fine on 16:9 and 16:10 monitors with 3x or more the pixels.