The screaming isn't actually as noticeable when you're there tbh. I think it just gets picked up by the vids, or it could be that the people fannish enough to risk expulsion by filming illegally (or 'subtly scratch their chests with their cameras' to paraphrase the almighty Misha)are likely to be the overexcited noisy ones ones...
I'm absolutely, definitely going next year. Even if the J's or Misha don't go, it'll still be cool. Malik and Gabriel (Henderson and Andy) were fabulous, as Richard Speight and Frederick Leherne. Jim Beaver's a definite for next year, and I'd love to see Bobby, he's awesome enough.
On the subject of Misha...
Now, you know I was a fan before I went, but I had a huge epiphany on Saturday. I realised that, for me, Supernatural has become more than the Sam'n'Dean Show (although it so is, couldn't have Show without it) I realised that Castiel has become as important. I can't imagine it without him now (not saying if he went I wouldn't watch btw)
I also had a minor freak when I realised that queuing for Misha's autograph equalled shaky hands and butterfly stomach whereas talking to Jared was absolutely fine, even though seeing him in the flesh was enough to suddenly understand Samgirls. Dear god he's hot. And very very big, and adorable. He thought my picture was cool (made a montage of clean icons for them to sign)