To me - baseball has it nailed with their three year requirement.
You can leave from high school for the draft, go to JUCO and jump right in the draft OR you can go to college and play for three years before you're draft eligible. If you're a non-academic, you can be a pro, develop and teams like getting guys they can build up. If you want to improve your draft stock, you can play a year of JUCO ball, re-enter and hey - maybe the pot's a little sweeter. If you want a more structured developmental path - college is totally for you. And truth be told - the difference between High-A ball and the upper tier of D1 baseball is practically nothing in terms of top talent.
What that means is - for a kid who wants to play baseball professionally - it's a matter of the development path they want to take - and choose the best way to skin the proverbial cat. Not a gazillion dollar decision at 17. YES, the risk for injury is there to a degree, but either way - through bonus or scholarship - you have a fall back for an education. So the floor is only so low for you. And obviously the minor leagues in baseball are super important. There's a value on player development.
With the NBA - I just think there's an endless number of ways they can take things, from expanding the draft another round - to filling up their developmental ranks with interesting players, etc. And the college game might not have the tip-top tier talent, but the overall floor - I think - will come up in a major, major way like we've seen in baseball.
Baseball has a monstrous talent distribution relative to other sports. Conferences like the Big West (Cal St. Fullerton, Long Beach St, UC Davis, UC Irvine, etc) are power conferences in baseball. The American has been like 2 or 3 in RPI and now adding Wichita State - that'll be a fantastic baseball conference this year. The SOUTHLAND conference is usually a top 7 or 8 conference. My point is - teams can compete or at least have a chance to with really good coaching. Programs can blossom and emerge...
And yeah - the really good schools will likely remain really good schools. Distributing more talent and carving off the tippy-top hasn't hurt Texas much. Hasn't hurt Florida State. Or Southern California. Or Fullerton. Or Miami. Or LSU. They're still the big dogs on the block. But TCU and Vanderbilt have emerged as super powers. Southeast Louisiana and UConn are on fast tracks to becoming REALLY good programs. Southern Mississippi, Sam Houston State, Dallas Baptist, Missouri State - they've all cemented themselves in recent years as programs that aren't going away anytime soon. The Atlantic Sun has produced the National Player of the Year a few years ago (Max Pentecost) and Chris Sale within a few years of each other.
My point is the little guys have a real chance to do real damage and build themselves. Coaching begins to mean something. Rivalries and building things (other than facilities, by that I mean culture, tradition, systems and the like) mean something again. So I dunno - i'm excited to see one and done go away forever, if they can make it happen.