I'm a little surprised the NBA would be in favor of this. They'd get the Lebron, Kobe, Garnett type talents a year sooner again. But there were plenty of busts before and getting a look at the players for a year in college gave NBA teams a better idea of what they were getting and protected them from themselves to some degree.
I think overall I've liked the one and done rule even if I'm mixed about some of the things it's created in the game. More talent in the college game, if only for a year is good. Haven't cared for the byproduct of the system whereby Duke and Kentucky can stockpile as many of them as possible for a run at the National title and then just keep at revolving door of them flowing through. But also at the same time it's made it interesting in that there are more different ways one can build a team, and it makes programs think harder about how they want to recruit.
I think if instituted, we'll see more players entering straight out of High School than the last time around. I do wonder how many players will then leave after 1 year of college. I'd think most if they were good enough to leave after one year will also have been good enough to leave straight out of High School.