It seems like most people who want Toine back want him back as just a mascot. Sit on the end of the bench, waive your towel, collect your ring, and then retire as a C. It would be a nice ending to the story, but very doubtfull. Antoine wants to play, he can sit at the end of the Grizzlies bench and do that now. He's not going to come here not to play too.
Another thing with Antoine, if he ever did come back (again) to the C's this year, it would be about a year since he even played a game! The last time he actually played in a game was February 19, 2008 for the Twolves. I think even the Antoine supporters will admit that his game has seriously declined over the last few seasons, how much more do you think his game would have declined without having played a game in a year? Or how much more decline has there been that we haven't seen since we haven't seen him play in so long? Of course there is the counter argument that he would be well rested and his aging body would respond better and he would be more fresh (ala PJ Brown last year), but that theory doesn't work as well for someone with Antoine's skill set.
As for Antoine as a coach. I don't know, I think he would make a good coach. He's very personable and talkative and says his mind - all good qualities for a coach. Say what you want about Antoine, but you can't deny he knows the game (just because he doesn't act on it, doesn't mean he doesn't know the game). And all reports were saying he took Al Jefferson under his wing in his half season back here, and Al's looking pretty good to me, maybe Antoine was responsible for some of that (although Al isn't jacking up 3's, so who knows how much influence Antoine really had on him

). Also Antoine has won at every level, been a franchise corner stone, come off the bench, and gotten DNP-CD's so he could probably relate to all players. But the thing I think that makes former players good coaches is passing/playmaking ability and this has always been one of Antoine's strengths. People want to just remember Antoine as jacking up 3's, but in his glory years here he did do a very good job of running the offense as a point forward. In his short lived prime, Antoine probably was labeled around the league as one of the best point forwards out there (just my opinion - I have no facts for this). Most of the players turned coaches are guards/playmakers: Larry Brown, Scott Skiles, Larry Bird, Magic Johnson, George Karl, Isiah Thomas, Doc Rivers, Avery Johnson, Terry Porter.and even potential canidates like Mark Jackson, Kenny Smith, and Sam Cassell all either guards or playmakers. Guys like Mark Jackson and Avery Johnson get offered jobs with no experience while stars like Patrick Ewing and Kareem don't get offered any jobs despite working as assistants and starting at low levels. I think it comes down to what skill sets translate good to coaching. Players with good passing/playmaking ability generally make good coaches. I've never seen a stat, but I bet the majority of player-turned-coaches were either point guards or playmakers. So based on this (as well as the personable, talkative, etc. traits I already mentioned) I think Antoine would make a good coach,
if he wanted to be, but who know's if he has any desire to do that.