One of the big changes from the PTR to the live realms is that CC non-breaking effects have been removed. You cannot Multi-shot with CC targets up and get a way with it (or a number of other abilities). This has been confirmed by Hortus, and thanks to reader Meph for pointing this out. However it should be noted that in the patch notes, Avenger's Shield will still not break CC. This is interesting and will be explored more once the game comes up.
You should be seeing the downloader finish about 10 megs worth of content, and then update the game. Everything went smoothly for me on both my Mac and PC clients.
WoW Insider will continue our extensive coverage of patch 2.4 today!