I'm just getting started with Rondo.
Rajon Rondo, to use Doc's words, has been "phenomenal" in stretches. All that he needs to do is to start contending for 24 more minutes a game. I believe right now he pushes the ball for somewhere in between 12 and 24 minutes. I don't mind him slacking for a quarter, just for him to watch the opposition and start seeing the gaps in their D as he tests it, as long as he picks it up before we're behind 10 points.
As for his shot, which is worth mentioning again imo; I think his willingness to take shots every now and then is really good. Especially the ones that are important, the shots he's been taking at the end of quarters. They mightn't have been the -right- shots, they mightn't have been off plays that have been drawn up for him, but at least he's hoisting them up. And that's a willingness we haven't seen yet.
Which leads us to his 'form' and shot percentage. The fact that he's a lousy shooter (at best) right now can only change if he actually takes shots. You need to be fairly coldblooded to make every shot and you can just tell that Rondo's biggest problem is his nerves. Everyone knows that a true shooter knows his next shot will be all net. Rondo however, thinks his next shot might miss. The aforementioned lack of faith in his own capabilities make him inconsistent.
Consider this:
Have you seen him shoot those trickshots? Behind the backboard? Weird falling-forward-spinning-to-the-backboard shots?
He has a knack for those. They always come very, very close to being true, or they actually are true. You never see him throw those totally off the mark. I believe that's because he shoots them with confidence. He takes them when he *has* to, when he's forced into a difficult position and can't do anything else but "trick it up".
Now, if he had the same confidence when shooting a normal jumpshot... I think he would be awesome.
I honestly believe, if we give him enough time to adjust and let him take those shots, he'll start hitting them before the end of the year.
.edit:
Defense-wise, I think Rondo has improved greatly. When he actually tries, he's really good at keeping in front of his man.
Note the "when he tries" bit.
He seems to get 'tired' quite soon, which results in lack of attention and he'll just go for the steal as soon as he notices a fake, instead of adjusting his own movement to keep in front. I believe it's part of his instinct, which is rather hard to get rid of. I've seen him improve though. Others have too (through I read that Danny and Doc for agree on this, for example.)