I'm all for the one international prospect spot per team. I mean, come on, who doesn't love prospecting?
The problem is that there's no great mechanism to add these prospects to our roster, unless they're already there. A team with 16 players can't claim them off of waivers, meaning that there's an inherent advantage for teams who already own guys playing abroad. They'll get to take advantage of essentially a 17 player roster, whereas teams with all NBA players will only be able to have 16 players.
It's a neat concept, and I'd like to discuss it a little further. It would have to go into effect with next year's draft (since lots of folks have already made roster decisions), but it's worth discussing.
EDIT: I missed the part where WW suggested it for next season. Under those circumstances, I think I'm on board. It potentially prejudices teams that have dealt draft picks, but otherwise there's not a lot of harm.
To further level the playing field, what about a tweak that only guys added to rosters on or after next year's draft are eligible? That way, teams that already have a bunch of international guys aren't given an unfair advantage (which amounts to an extra roster spot). Of course, that can be a bit of an accounting nightmare, so I don't know.