A note in an mmo champion post indicates that patch 4.4 will a prep patch for the next expansion. It has some confirmations from the rumours of the patch 4.3 Deathwing events, including the next 5 mans – but really the idea that 4.4 is a prep for the next expansion is the bigger news.
Patch 4.4 will bring a world event before the next expansion. The next expansion should be released with a “meaningful difference” in the release timeline compared to previous expansions.
Now if it takes ages to appear then its kind of a moot point, however I think this indicates that Blizzard are far closer to the next expansion that they would normally be.
I expect them to compete in some way with Star Was because of the number of folks who have declared that they will be leaving or have already left. Makes me ponder though – perhaps they would be better waiting 1-2 months after the SWToR release, so that the people know that the new expansion is coming, and those who are not happy with SWToR will return.