In the recent Activision Blizzard Q4 Conference Call, it was stated that Blizzard feels the beta and auction house testing are going well. However, they also stated that their current target for launch will be in Q2 (April, May, or June), not early 2012 as previously stated.
One of the likely causes for the release being pushed back is the re-working of the skill and rune systems. Even though it hasn’t been very long since beta patch 10 brought massive changes, we will likely see the current implementation of the skill system in another patch very soon. However, we will not be seeing the rune system changes in the beta- the best we can hope for is the community site to be updated.