A sidebar throughout forums is pretty common - it's never been on GOT before beyond the home page because I've always needed to limit the information "pulled" per page to keep the site online - some will recall when the site used to crash whenever Everton scored a goal, or conceded...
Anyway, I saw a sidebar on an Arsenal forum and it included things like the league table and various other bits (like login/register section on our most active pages) and it worked quite well I'm just testing core functionality before developing it - if we continue with a sidebar, it'll be user collapsible (so you can close it) and it wont have the white space that currently exists.
It's not revenue driven, if it was we'd just slot an advert right aligned to the top post of every thread.
I think the data the sidebar uses (members online etc I understand is quite a resource hog) will mean it'll likely be binned anyway.