This is annoying me as well; weirdly I didn't get this update until I manually checked, despite the auto-updater running itself just this morning! I got the "clicking icon in taskbar doesn't open a new window" bug and was trying to see if it was fixed in a newer release, and now I'm lumbered with this awful sidebar change in addition...
I think it's very telling that there's also now the "Easy Setup" button permanently welded into the Address bar... Are we really expected to need to change the settings so often that we have to have an access button on permanent standby? If so, who the heck considers that to be acceptable design?!