The big aspect was as Treantmonk broke down what is left to playtest and how much time actually remains.....it makes sense. Realistically the next playtests are going to have to be PACKED to cover all that content.... and so either they go more conversative with which they know works, or they abandon the playtests to go more experimental, which is a roll of the dice. Seems they chose the tried and true.
The biggest ? to me is the monster manual. Again based on limited playtest time, it seems likely they will focus on tweaking and adjusting monster stats rather than bringing out major changes in mechanics.