Aside from Wade, nobody else on Miami is at a risk of running out of gas, completely, in the playoffs. That includes the older players, like Ray Allen, Mike Miller, and Shane Battier, who are playing spot-up shooter night in and night out...and nothing more.
Wade is a curious case because of his injuries, kind of what we saw with Allen Iverson later in his career...but the difference is, Wade knows who #1 is in Miami. It's not his city anymore. Some nights, he can even defer to Chris Bosh, and the Heat can still log the win.
Major winning streaks come from major contenders, and a lot of times, champions.
72 Lakers (33 wins) - champs
71 Bucks (20 wins) - champs
00 Lakers (19 wins) - champs
70 Knicks (18 wins) - champs
96 Bulls (18 wins) - champs
For teams 18+ wins or above (and not extending into a second season), I left off three teams. Two of them (2009 Celtics and 2008 Rockets) lost a significant player before the playoffs (Garnett and Yao). There's a STRONG chance Boston would have won the 2009 NBA championship with a healthy Garnett...don't care if I'm on a Lakers site or not, it's true. Ariza was not going to stop Paul Pierce.
Anyone remember what Houston nearly did to us the following season...without Yao Ming? We were the 2009 champs, who almost lost to a dismantled Rockets team that year. Sorry, but Houston probably beats us if they had Yao in that playoff series. We dodged two bullets.
The other team I left off (the 1982 Celtics) were defending champs, and went on to win a couple more in the next five years. They also lost (in the playoffs) in seven games, to a team that would go on and win the NBA championship the following season, the Sixers.
No team in the league is more dangerous than the Miami Heat right now. It's not even close. The Spurs may be able to beat them and end the streak soon, who knows, but in a seven-game series, no team will get the job done...and it will take an injury to one of the big three (like Boston needed from Bosh last season), or a couple of shooters to go down, for a team to knock them off their pedestal.