I think it might be a bit ridiculous to include teams in this poll that just aren't expected to be any good. Memphis, Golden State, Sacramento, LA Clippers or Indiana. They aren't supposed to be that good, as a matter of fact they are probably 5 of the worst 8 teams in the league. A meltdown can't happen if an implosion is already expected.
Now, if by meltdown you mean there will be drama and histrionics and player confrontations and outbursts, yeah, there could be that stuff at some of those places, but isn't that to be expected?
I think Orlando is probably the leader in the chances for a meltdown as a good team blowing up to become something less. We have already seen Howard go sour and level stuff at his coach. We have seen Van Gundy go out and blame everybody for his shortcomings as a coach except himself. And now, they have made the quintessential David Stern era superstar, a superstar that is flashy and scores a lot and is marketable but doesn't have a clue as to how to be a winner, namely Vince Carter, their big off season addition. Carter is a born chemistry killer and his addition moves Lewis out of the PF slot where he was such a great mismatch. SFs across the league will have no problem guarding Lewis.
I also can't believe no one has mention Houston. Tracy is coming back to a team that went deep in the playoffs without him and for part of the playoffs, Yao. Now he comes back from yet another injury and needs to prove to the NBA that he is still worth max deal money. What happens when the core of Rockets that got the team so far last year starts seeing losses because TMac can't and won't play defense or play unselfish team offense. I see major meltdown happening in Houston.