As far as the players go, can't say whether they have improved until they play but due to the coach, it should be expected that most will be better.
My analysis:
Center: Considering Murphy could play alot there, much improved. Rason, Murphy is better than Foyle and has more basketball skills right now than Biedrins. Not counting Murphy, expected slight improvement because Biedrins should get better, O'bryant is decent but not special yet, Foyle will get less court time and Taft, if healthy, might play some Center and he is capable of being a good player also.
6.0 out of 10 (with Murphy counted), 4.5 out of 10 (without Murphy)
Forwards: If JRich plays a fair bit of Small Forward, then that makes the frontline much better. If he doesn't, then it is up in the air. Dunleavy is the probable starting SF or PF, (depending if JRich starts at SF), and he has been nothing but awful and is coming off a season where he actually got worse! Yepee

. Maybe Dunleavy will be better under Nelson but I just don't see it because it is the shooters and slashers that do great with nelson and dunnyboy is neither right now. A fairly nonathlete, Dunleavy has got to at least shoot better and try to rebound a little more, 5.5 would be real good........ for him. Mickael Pietrus is a disappointing prik that is on his last chance, at least to me and has to do somehting positive. He is a monster athlete who should have picked up more skills by now! He can shoot alright (on and off) and defends well but he has been a better defender than he has been recently. If Pietrus is used well in the run and gun style (which is really possible), picks his spots with outside shooting and gets back to enjoying stopping players from scoring, he could well be the third most effective player on the team! Ike Diogu is perhaps the player I have the most high hopes for in the next few years (if Nelson decides to use him which may not happen because half court stuff is not his most liked offense). Diogu has great inside post skills, jump shot and incredibly long arms that can make him a very good rebounder and shotblocker like he was in college. He is also built strongly which will only mean that he will be effective both offensively and defensively. Diogu could be the third best player this season! Cabarkapa will likely be a garbage time player but he does have quite good mobility and skills for a 7fter so he might get more time than expected. Taft, if healthy, could really get some minutes because he has the physical skills to be a very good player in the run and gun, both offensively and defensively. Devin Brown may get Pietrus' court time if Pietrus turns out to be a bust this season but Brown will likely get next to no time as well.
8.5 out of 10 (with JRich), 7.5 (without JRich)
Guards: The best position for the team! JRich has always gotten better every offseason and maybe he will get even better again. JRich is one of the most talented and young SGs in the nba and he may have superstar capablities, at least allstar type already. He should be the leading scorer but it'd be good if he could improve his defense, if even just a bit. The X factor of the team, to me at least, is Baron. Baron Davis has to play more games a season! end of story! having him around for two thirds is not enough and not worth what the prik is getting paid! He is a great player and potentially the best PG in the nba. Most glaring aspects of his game are his shot selection and shooting percentages, so he has to not throw up the ball so often and when he does, be more careful. Monta Ellis looks great and could be such a steal! If he starts at SG or gets over 20mins a game at least, he should be one of the best players on the team. He just has to grow and improve and he would have done his part so far. Noone else worth mentioning.
9.5 out of 10 - One of the best backcourt rotations in the nba if not the best!