I don't think Melo will ever be an outstanding rebounder, because he's not a natural banger, but he should be able to tip lots of balls to teammates, in addition to grabbing his share of boards.
I think 15 points, 8.5 boards, and 3+ blocks per game is realistic for Melo eventually, especially playing with Rondo.
If he's putting up those numbers and getting named to 1st, 2nd, or 3rd team All Defensive Team, that's Tyson Chanlder/Marcus Camby-ish right there.