It's always been crazy since the Oblivion forum came. I was mostly active on Community Discussion there but as the TES noobs we could call them started going beyond the Oblivion forums they just ruined everything. Been a long time since I've set foot in TES Forums, went over here insted - Much better forum with less people which makes it easier to know everyone else better...
So to you're question, yes I've noticed that the quality if we could call it that on the TES Forums have dropped since Oblivion came, not much we can do about it - I recall seeing a post about preserving Community Discussion quality since people are flaming and behaving childish...