You can read more about this patch at WoW Insider's Guide to Patch 3.1 (including the latest patch notes), and read some impressions of Ulduar fights. We've also covered the initial release of Hodir.
Hodir has been tested a couple other times on the PTR, which means the fight is getting more and more refined now. This does not mean that patch 3.1 is close to being released on the live servers, but just that some of the fights are getting a good workout.
Update: The live stream came and went, and the PTR testing is over tonight. Stay tuned for more tomorrow!
Patch 3.1 brings us Ulduar, dual specs, significant changes to all the classes, and more! We've got you covered from top to bottom with our Guide to Patch 3.1.