I'd rather see Y2J in TNA. WWE has booked Jericho very poorly at times, though, if he were to go back to the 'E, that would give me incentive to start watching again.
But frankly, just imagine the kinds of matches he could have with guys like Sting, Abyss, Samoa Joe, AJ Styles, Christopher Daniels, and others. Man, I would LOVE seeing some of those!