This is an extension of the rule for collegians which basically says the same thing. The new rule is very likely to create a situation far worse than it is now. Recruiting will become a totally out of control process, as schools will now have to not just evaluate talent but also intentions. What would a Chris Burgess have done under this rule? Elton Brand? Raymond Felton? Julius Hodge? And how do you decide about these kids?
For the kids, it's not that great either, first for the obvious reason: so many of them will be suckered out of an education and left with a handful of change. But not everyone understands that the team that drafts these kids retains their rights for years. Imagine Chris Wilcox for some reason had decided to test the waters as a senior and had been the last pick in the second round. That would have cost him millions.
The NCAA needs to quit screwing around and address all this stuff systematically and coherently. Ideally, the NCAA would sit down with the NBA and the union, and a panel representing the NCAA's players, and work out a coherent system to manage this mess.
How about this? The league and the NCAA co-manage a Pro-Am Summer League, where players are supervised and systematically advised on their potential and their weaknesses. It would allow them to compete against NBA level competition, to get candid and unguarded advice from professionals (in the high sense of the word), and to escape the endless parade of agents, flatterers, and hangers-on who convince them they are ready when they are not.
If you added an age requirement, then you've got a framework that is workable: a realistic assessment of talent and draft potential, and a semi-mandatory apprenticeship. At that point, everyone wins: the players are prepared and knowledgeable, the NCAA is predictable, revenues increase for everyone, and the kids who aren't going to make it will have an inkling and so can start making alternate plans. Really, though, if it's not approached intelligently, both games will be destroyed, and that would be a shame.