Like Amanda Dean and GotFrag themselves detailed the other day, there are a lot of teams to keep an eye on this time around. Frag Dominant took the win last month, and there are plenty of other teams you may recognize. SK-Gaming, MoB, Got Game East/West, Pandemic, Fnatic, plenty more. If you don't keep an eye on the PvP scene on a regular basis you might not recognize those names, but they put on a good show last time.
To view the live stream, you will probably be prompted to install a codec if you don't have it yet. All of us WoW players are a little paranoid these days (with good reason), so don't be afraid to run a background check on anything you're asked to download. I'm pretty positive there's nothing to worry about in this case, but better safe than sorry, eh?