I like the idea of dropping from 82 to 76, the slight issue is that might make career records a little harder to achieve.
I can't see them changing the playoff structure though, as it is it's not as if teams in 6th/7th/8th are making deep playoff runs. And, on the rare chance that they do, a ton of people get behind them (because everyone likes cheering for the underdog). The champion pretty much always comes from 1st-4th anyway. But, if they were to cut the number of teams, that would be a huge revenue loss for the NBA, and I really don't see them going for that.