Noel will not be a bust. He is a once in a generation defensive player. He's smart enough to be very productive on the offensive end as well. He can pass, and I believe he will develop an offensive game as well. His weight does not concern me at all. He is only a teenager!
Rondo however, is a transcendental player. He is in the same level as Chris Paul and Derrick Rose. His value has taken a hit due to his injury of course, but if one were to believe he will come back fully healthy, then this is not enough. Taking that deal is essentially selling Rondo low. One only does that if one believes that he will no longer be the same player. Then absolutely you do this deal.
Personally I wouldn't trade Rondo for that package. Although I believe Noel will be an above average player in the NBA and that future first, if used properly, will become another starter in the league.