Here are a list of the Q&A on the Roonie 2K's twitter stream, it is all around the MyTeam Mode:
Can you have a '98 and current Kobe on the same team?
Answer: No players are unique individuals regardless of year
Are lineups position specific, can you field 12 PGs if you wanted to?
Answer: Yes, but obviously you'll pay the price where bigs do the work
How many player per roster?
Answer: Total 12, 5 starters and 7 bench
How customizable is the MyTEAM?
Answer: You can choose Home & Away uniforms, court floor, playbooks, and Head Coach
You can't play your team against a friend's team. Road to Playoffs is against random opponents this year. You can't put your MyPLAYER in MyTEAM