I think that your '92 Dream Team, Jordan's Bulls, and Bird's Celtics are great additions to the game. I realize that it might be a lot of hard work, so I don't expect you to add any new teams in the next patch, or even patches in the near future. However, if you do ever decide to add some more teams, here are a few suggestions. I've seen some other patches with past teams for ever franchise in the league (and then some), but to keep the work low and the game from being cluttered, I think you could just add a select few of the most famous/greatest teams ever.
-Bill Russell's 60's Celtics Dynasty (longest lived dynasty EVER)
-The Showtime Lakers (a must have if you're gonna have Bird's Celtics)
-The Wilt/Jerry West/Elgin Baylor Lakers
-Kareem and Oscar Robertson's champion Bucks
-The stacked Knicks championship team of the early 70s
-The Bad Boys Pistons
-Kobe and Shaq's 2001 Lakers (rampaged through the regular season, 16-1 playoff record)