You can definitely see the tweaks in their offense. They've always been unselfish, but last year, especially in the Finals, it was more catered to Parker breaking the defense down (either via one on one, or off the PNR), and creating either for himself or for someone else (mostly Danny Green). The Heat's PNR defense ramped up (which is saying something, as they play it very aggressive as it is), Parker was exhausted by the end of the series, and LeBron was able to curb his penetration at the end of games 6 & 7. Manu having such a bad series (outside of Game 5) probably cost them the series (well, that, and the disastrous end to Game 6).
This year, Manu is playing well, but the offense is a completely different animal. They're relying less on the PNR, and more on making sure the ball doesn't stop moving. Don't misunderstand: the PNR is still there every time down the court, but it's used more as an ignitor of the offense, as opposed to a finish. They're allowing the Heat to consistently play themselves out of position, and continually taking advantage. It's crazy, cause the Heat are known for playing very aggressive defense when the games get big, and it's always worked. However, after last year, it seems that Pop recognized that, and thus the subtle shift in their offensive philosophy. What was Miami's biggest advantage has now turned into it's biggest detriment.
Spo gets alot of heat (no pun), but what is he supposed to do (on defense atleast...offense is another issue)? Ever since the Big 3 have been there, they've hung their hat on their aggressive defense, and now it's being exploited masterfully by Pop and his well oiled machine. Can't do anything but tip your cap. Their best is better than your best. Atleast up to this point...