No one can say for sure, I personally think that the iPad 2 is pretty much guaranteed to get the update. iPad 2 is still being sold officially as the entry-level iPad model, and Apple usually releases a version of the update for any device which is still being sold. iPad 2 is also just as powerful as the iPad mini, which WILL receive the full update. The iPad 2 won't receive all of the features it's more powerful successors will, though.
However, as iPad 2 will probably be dropped when iOS 8 is announced, I recommend jailbreaking your device at as late a stage as possible.