Another factor in the NBA's popularity is that, whether we like it or not, the league is most successful when it has megastar players on successful teams in large markets. And if that team happens to be the Lakers, the NBA couldn't ask for more than that.
As for the topic....If the NBA does prefer to go with the "marquee, banner carrying guy" strategy, my best bet guess at who could end up being the choice would be Yao. Factors that would help Yao meet the criteria are:
1. His playing level...he must continue to develop his game and his on court "at ude" and he must CONSISTENTLY deliver the performances that we've seen glimpses of. "IF" he puts it all together, he could definitely dominate the league.
2. His personality...great sense of humor, very quotable, well rounded and grounded guy. It's hard to find anyone, media or fan, who flat out doesn't like the guy.
3. Marketability and Popularity...on a worldwide level, almost certainly already the most well known current NBA player.
4. His Team and Market...now partnered with another player with MVP type talent of his own on a team with a measure of historical success and in a large market. At ages 24 and 25, and with both Yao and TMac expressing their intention to stay with the Rockets long term, Houston's chances for future les increase greatly.
And so do Yao's chances to be the NBA's poster child.