Aside from the aforementioned Mayo, Gordon, and Westbrook, Rose has been a stud.. although its not really as surprising.
Brook Lopez has been pretty solid. His FG% could be a little higher, and he's certainly getting big minutes (28.5 per game), but I didn't think he's given NJ some needed help on the glass and hasn't been a slouch offensively averaging dbl figures.
Augustine has impressed me as well. He may force Felton out of town in the next couple of years.
Fernandez has looked for Portland, although he's had some quiet games recently. Its a shame Oden hasn't been the rock down low they were hoping for.... I suppose its still early.