If you're unable to attend the Worldwide Invitational in Paris, don't worry! In addition to WoW Insider's own coverage of the panels and various announcements, Blizzard has arranged a live feed for their opening ceremony, closing ceremony, and all of the tournaments and concerts in between. It looks like they'll be running two feeds at once, one at their Main Stage and one at their Tourney Stage, so there might be more going on than you can follow! In addition to having two feeds, each of them has a low quality and a high quality feed available. Have an awesome connection? Stream both stages at High! Personally, I'll have the Main Stage going at High Quality nonstop, but maybe not the Tournament Stage so much.
I (and Blizzard) recommend taking a look at the live feed page before the convention begins, so you can prepare any software or plugins you may not have yet. If you tuned in for the 3v3 tournament on GotFrag awhile ago, you should be all set already. If you haven't, you'll need to pick up Octoshape and install it. Instructions and requirements can be found on the Octoshape website.