It's amazing what the Miami Heat have done so far in the three years they have been together. You have to go back to the 1996-98 Chicago Bulls to find a 3-time Conference Champion in the Eastern Conference, back to the 2000-02 LA Lakers to find a 3-time Conference Champion in the NBA.
The Heat have done well, but it
is the east, afterall, so kind of mitigates the accomplishment, IMO. If they'd done it in the west, well that would have been something.
But if they pull this off, get their third title in franchise history (and since 2005-06), they will tie themselves with the Phialdelphia 76ers, Golden State Warriors, and Detroit Pistons for 5th-best all-time.
Wait, the Warriors have 3 championships? I haven't put the Google on this yet. Did they win 2 when the franchise was in Philly? I know they've only won 1 since coming to the Bay Area.
All in all, I think if they win this title, we can call Lebron's tenure in Miami a success. If they lose, they will have something to prove next season. Remember, Danny Granger and Derrick Rose will be back next season. Teams like Washington (John Wall, Bradley Beal, Emeka Okafor, Nene, #3 overall pick) and Cleveland (Kyrie Irving, #1 overall pick, Dion Waiters, Tristan Thompson) look to be much improved next season. Remember, Detroit and Atlanta have deep pockets this summer to reshape their rosters. Brooklyn is a year older. And new salary cap restrictions will be put in place before the beginning of next season (the graduated Luxury Tax) that will affect the Miami Heat's roster. Dwyane Wade looks old and has had 2 straight postseasons with knee injuries that have limited his effectiveness.
Out west, San Antonio and Memphis may not be a threat, but Russell Westbrook will be back. Dwight Howard and Chris Paul will be free agents, possibly changing the outcome in the Western Conference. My point to all this is that Miami may not have as clear of a shot at the second NBA title with Lebron next season as they have right now. That will be great from a competitive standpoint, but not from the Heat's point-of-view.
Here's hoping they beat Duncan's Spurs, who have never lost in the NBA Finals.
Considering how hard it is to win an NBA championship, I think you could call LeBron's decision to go to Miami a success after last season.
Barring injuries (to Miami and Indy), I don't think any of the teams you mention will be serious championship contenders next season. Chicago might be if they can somehow manage to find a consistent offensive player besides Rose. So, you don't like the Knicks?

Actually, they are as flawed a group as any in the east -- an odd mix of offensive talent who still don't play much deffense.
You don't think SA or Mem will be a threat next year? As long as the Spurs have Pop, Manu, Parker, and Duncan, they can contend. The Grizz just need to hold onto their coach and they will too, I think. But I agree, OKC will be back in the thick of the west mix next season.
The Heat have looked like a team trying to go back to back this playoffs, kind of ragged when they shouldn't -- that happens when you're trying to repeat. OTOH, their lack of competent bigs may really be a problem for them. I am looking forward to this Finals like I haven't since the Lakers reached down the throats of the Celts and took out their hearts in 2010.