*Edit* I changed the title cause I realized it was causing negative vibes.
In this draft, there's no one we can take at 30 who will contribute next seasson (unless Jason Maxiel and Rodney Stuckey are re-entering this year's draft). Actually, there is a chance that college upperclassmen like David Padget and Sasha Kaun could find time on the court, since we lack depth in the frontcourt, but they aren't going to be used meaningfully.
So rather than going with the "go with the most ready player" route, Ainge should do what he does best and take the player with the best overall talent--regardless if it'll take time for him to develop.
As we are currently constructed, we have areas to fill.
PG
I think our depth here is at least adequate. Rajon absolutely needs to develop a nose for offense. He's got 15 ppg in his pocket if he looks to finish his penetrations in the lane and take open jumpers. With all the attention paid to Pierce, Garnett, and Allen, Rajon gets a lot of opportunities that he doesn't capitalize on. By looking for his shot, he'll find his teammates open for easier shots near the basket. Doc doesn't incorporate an offense that stresses the PG creating shots for the team, but Rajon has had some big assist games, which shows his keen eye for passing the ball. His quick hands translates well to fastbreak points.
Right now, Cassell and House are our backups, but in time, Gabe Pruitt stands to inherit the role. He's nothing more than a backup PG, but he can find more value as a shooting/scoring threat. He's a good shooter, and if he develops aggressiveness at this level (the type he showed in the D-League), he'll get a good share of minutes on the floor.
Draft I'm not in any rush to grab a PG, but at 30 I may look at Mario Chalmers (whom I have liked since high school). I'd rather see him taken in the 2nd round, but his pesky defense and solid scoring ability doesn't make him such a stretch with the last pick of the 1st round.
SG and SF
Once Pierce and Ray Allen are gone, we are thin at the wing positions. I am a fan who thinks Tony Allen is a keeper, and if he commits himself to 500 jumpers a day and countless ball dribbling exercises in the offseason, will be our starting 2 when Pierce and Allen are gone. Tony holds himself back from being a force. Confidence and focus are his stumbling blocks. Getting over those hurdles will set Tony free to be an incredible player.
I'm open to give Gerald Green another shot. I think he was hit with 3 huge wake up calls this past season. 1) Ainge traded him away (he was Gerald's biggest supporter), 2) the Wolves traded him away (never got his feet set in MIN), and 3) the Rockets released him (though it was because of limited roster space). After being selected 18th in the 2005 draft, and showing glimpses of tremendous upside, Gerald is unemployed after just a couple of seasons, and questions about his attitude has surfaced. That must be alarming to him and his family. This should be the kick in the pants that a young player needs to dedicate himself to whatever it takes to succeed in the NBA. He's still got tremendous upside--he's got terrific touch and range on his jumper and he's got athleticism. His weak points are his dribbling, footwork, and shot selection. Very correctible areas. If Gerald is ready to kill himself in offseason workouts and be willing to do whatever Ainge and Co. tells him to do, his young career can still be rectified. A future wing combo of Tony Allen and Gerald Green (both developed, of course) has some promise.
Draft At 30, choice talents are slim pickings, but if Brandon Rush happens to fall, I'd take him. He's got parts of Paul Pierce and Ray Allen in him. He's got Pierce's body style (not as much meat, but has room to pack on some muscles on his broad shoulders) and Allen's smooth game. He's got a jumper (needs more consistency) and he can drive to the basket (but must show more toughness). He seems to have fully recoverd from his ACL injury and shows absolutely no ill effects from it.
One player I absolutely want falling to 30 is Nicolas Batum. He's the type of pivitol player who helps a team's versatility. He's the european version of Tayshaun Prince.
PF and C
Right now, we have Garnett, Perk, PJ, Baby, and Powe. Take away Garnett and PJ, and what we are left with in the future are Perk, Baby, and Powe....not exactly the pillar of dominance in the paint we'd like to have. Perk does have his value. He's a defensive presence with occasional spurts of offense. But he is not going to make the All-NBA Defensive 1st or 2nd team (maybe 3rd team one day) and he isn't a big time rebounder (his hands aren't good and he can't get off the ground more than once when leaping for rebounds out of his comfort zone). On this team, with 3 star players, Perk can excel by focusing on his limited role. On a team with lesser talent, Perk must offer more--and I think he can, just not that much more. As for Baby and Powe, I think if we could join the two, we'd have our PF of the future. Baby has the quick feet and brute strength, but his short arms and lack of vertical make him a candidate for the player who gets blocked the most in the NBA. Powe has freakishly long arms and excellent post moves, but he doesn't have the lower body strength to control his area in the post. Both have flaws that will keep them from being big time players.
Draft No big name PF or C will fall to 30, but sleepers may be found. Nikola Pekovic could be a scrappy big man who adds a touch more offense than Perk (but we sacrifice some shot blocking), and both Richard Hendrix and DJ White can come in and battle Baby and Powe for playing time right off the bat. Another sleeper is Devon Hardin--an athletic and muscular 6'10" big man who can get up and down the court well. He's got the goods--but just hasn't delivered them. Nathan Jawai looks like he can be molded into a formidable player.
We can't expect much with the 30th pick. If Ainge can move either Powe or Baby and the 30th pick to move up into the late teens, early 20's, we could get lucky with a player who slides that far. Otherwise, we're probably looking at getting a supplemental player who won't really impact the team, now or in the future.