Yes the new CPU's have a better Memory controller and the rated speed for the new CPU's will be 1866MHz. In some instances this may be lower, depending on the CPU.
Still no firm dates for any of the new AMD CPU's (Llano or Zambezi) or when they will actually hit the shelves. They were originally due around the beginning of June (7th was claimed date) but this seems unlikely to me, especially as we are only just now beginning to see some of the new 9 Series motherboards coming on-line. If it follows the usual pattern, these boards will be on the shelf a couple of weeks before the processors....... but, of course, I am only guessing!