More rumors. I always thought the timing of Apple's iPad releases was closer to Christmas than I would do. The March timeframe is close enough to Christmas that I'm sure there are people who both wait to get one knowing a new model is coming, or others that feel a bit bad that their 3 month old present is now last years model.
There are pluses of doing it early in the year: All manufacturing difficulties have long been worked out by the time Christmas arrives many months later. And it's given Apple something pretty huge to announce in the spring.
But I wouldn't be surprised if this year was different. The biggest reason this year woud be to get all their devices updated to the Lightning plug before this year's Christmas. That may even be the only change to the iPad 3--a new plug.
Using a version of the new chip that is in the iPhone 5 may let them get the iPad 3 back to the thinness of the iPad 2. I just don't think if they did that now that they'd have any big changes to do next spring, and if they shift the iPad refresh time to the fall, that is both good and bad..