I'm excited for the new raids, but I'm potentially more excited for a new LFR. It's a great way to run alts through and get some nice gear, all while enjoying the game from a different perspective than your main.
LFR on the patch 5.2 PTR will be open today through this weekend, and if your main or alt doesn't have the necessary iLevel requirements on the PTR, you can grab some gear from a testing vendor and be all set. Watcher explains in his full post:
We're planning on opening the LFR wings of the Throne of Thunder raid sequentially, beginning on Thursday, February 7, by 11am PST (2pm EST, 8pm CET). We will leave LFR open through the weekend, so hop on the PTR, check it out, and share your feedback!
The item level requirement for the 5.2 LFR sections is 480 -- if you can't meet this threshold, note that there are vendors with epic PvP and PvE set pieces that may help you reach it.
I want to emphasize here that Blizzard really does need your feedback on LFR. The designers listen very closely to what the community says, and a well thought out and reasoned argument does a ton of good.
We'll have our own feedback and LFR boss guide soon, so stay tuned!