This was exactly as I predicted and posted here about six weeks ago (MPC7457, 1.25 and/or 1.33GHz, ATI 9600, intro at Paris Expo). I also noted then that Apple might remove the L3 cache, which they did. Frankly, sometimes I even amaze myself ;-)
Don't know how much the removal of the L3 will affect performance. For the 12" PowerBook posters, the correct observation is that they removed the L3 cache from the 15" and 17", not that they added a cache to the 12" (the 12" always had an L2 cache, although the MPC7457 doubled the size of same).
Also looks like the new 15" got heavier and slightly thicker (although not by much).
Overall, a nice upgrade but not insanely great.