Actually, the BF3 background (grey/brown with orange/red streaks of light) looks pretty neat. Might be dimmed a little and it could really break up the blandness of the near-black we have now.
However, personally, I don't find that the box edges look any good. Out of place or something, just doesn't seem right. Plus, I think people get the reference to BF3 when they see the background. However, please don't forget that a large part of our community is WoT based and have got little to do with BF3..
About the tags;
They look better with a small 'o' in my honest opinion. Actually our tags aren't even SMo, but .SMo^ . Please take pride in the period and caret. (Not the way you put it in the topic title

)

"And then when someone says: 'Wait, that's starting to look silly. That's starting to look like a kids game.' Well, then we just pull the saturation back a little bit, add some blood and everything's good." - Interview with Jeramy Cook on the scenery art in Borderlands 2.