I'm glad you asked this question. The philosophy of the changes is, to me, more interesting to speculate about than any particular trade scenario.
People are fond of saying, "if you trade Kidd, you are rebuilding," implying that he is that extremely rare type of player around whom an entire franchise can be built (LeBron James, Shaq, Tim Duncan, Michael Jordan, Larry Bird, etc.) The reality is, he never was THAT caliber of player and most certainly hasn't been close to being one for about 4-5 years. I submit that you can trade Kidd without committing to also trading every veteran on the team and resigning yourself to the lottery for the next few years. Any plan for rebuilding through a youth movement means almost certain disaster short term and is ultimately more luck (in the draft) than anything else. It is, long term, not any more successful than trying to reassemble quickly with different veteran pieces, probably less so. For every Portland or NO Hornets, there is an Atlanta, an LA Clippers, a Memphis, a Charlotte, etc. If the only draft picks being offered for Kidd are lottery protected and mean combining them with only expiring contracts for over-the-hill players, then screw that strategy. If you can get back a player 5-6 years younger, millions and millions of dollars cheaper and who fits as well or better with the players you have remaining on the team, than that is a preferable move, IMO.
I have no doubt that Kidd could be traded (3 teams, if necessary) and someone like a Mike Bibby or Jason Terry brought in along with another piece (wing defender, draft pick, etc.). Either Terry or Bibby would save millions in yearly salary (though Terry's is long term) and fit far better in an offense that included Vince Carter than Kidd would.
Which brings up the next point: If you trade Kidd, should you keep BOTH Carter and Jefferson? That's a tough one to answer. On one hand, I tend to think "no" simply because they really play the same position. Vince, especially at this point in his career, would be a much better defender at the 3 than at the 2 and Jefferson is arguably less effectual than Carter at guarding 2s. He's also too small to play significant minutes at the 4. Either one of them would be more effective as an offensive hub if the other were replaced with a first class shooter. And RJ's production will likely take a hit when Kidd is no longer on the team to force feed him fast break opportunities.
But, then again, it's nice to have two guys who can score 20+ a night and create their own shot. I would probably keep them both for at least this season and see how they mesh with whatever pieces the Kidd trade brings.
I would also be curious to see if, in the perceived (if not actual) leadership vacuum created by Kidd's departure, RJ steps up and becomes a vocal leader who's not afraid to get in Vince's face when he's standing around watching from the perimeter half the game. I could see RJ doing that. He has that type of honest personality. I suspect he would have done so by now but felt it was Kidd's place and not his. With that obstacle removed, he may get the chance to prove what kind of leader he can be. Of course, even if that happens, it's far from clear how Carter would take it coming from Jefferson, a younger player who does not occupy the same status as Kidd, either in Vince's mind or in the mind's of basketball society generally. But I think it's worth a try for half a season.