There will be some teams who can maybe give them a run for their money. The Thunder, depending on how their lottery pick player turns out, and whether or not Jeremy Lamb can be a useful role player for them next season. They have some moves to make, and Westbrook obviously needs to come back 100%, but they can still challenge, especially if Wade remains gimpy.
The Bulls could still have a really good playoff run if Rose comes back healthy and ready to go. But it's been over a year for him now. We'll see.
The Pacers could maybe upset them if they get lucky, have some good off-season additions, and Paul George takes another step up the ladder towards stardom.
The Grizzlies could have an outside shot at it again with the right moves.
The Clippers, if they actually end up getting Garnett and Pierce and maybe some other nice moves, and then come together in just the right way, could make a run to a title.
Still, the Heat have LeBron, and that's enough to make them heavy favorites again next year.