I would be perfectly happy with Platinum staying exclusive to Nintendo if the opportunity presented itself. If Nintendo could collaborate with them with some of their old IPs (Star Fox, as most have mentioned) it would be a match made in heaven. On top of that, I'd KILL for a perfect Wii U port of the original Bayonetta.
Better yet, just fucking port all of their games like Vanquish, Anarchy Reigns, Metal Gear Rising, etc. to Wii U so we can have a perfect library of Platinum games on one, clean system.