Obviously you're polishing it, but I'll give some feedback and hope it helps you:
1) Landing page, the enter key event isn't submitting the login form, right?
2) Time stamp on chat
3) Close button on the search dialog
4) I like cursor: pointer;cursor: hand; on my action buttons
5) Maximize video option?
6) Vote up/down by user to sort queue?
I love the [# of un-viewed messages] in title bar.
You definitely have to use another computer for it to work. Browsers on the same computer isn't working--which it shouldn't anyway. Perhaps you could just detect if it's the same computer and put up an alert ("hey, you're a phoney! you're on the same computer!") then you won't waste a lot of resources to process that request.
The music synched on my 2 computer. Very cool. Please keep up the good work.
-V.