I don't see it happening (at least with the 3DS) unless Sakurai and team can finish the game sometime next month. Still I would imagine it would be considered something of a priority otherwise. The reason for Pokemon's uniform release was to help keep the game covert worldwide until release date (that and to help convey it's theme of unity through diversity). While Smash doesn't have the latter, it certainly sounds like Sakurai values the former (based on his previous comment on SSE cutscenes).
Again still, I don't see it happening. I would predict that the release dates will be closer together than they have been in the past (though in the case of most PAL regions they'd likely get gipped once again). It's not something I'd like to see happen but it is probably the reality in this scenario. I'm saying this mostly due to the prefix in which Sakurai has been speaking in his daily comments. The way he talks makes it sound like is that they are still working on development of the games. Typically translation work is done after the initial game is created to keep dialog between both versions as consistent as possible (seeing as text is subject to change in development). Now it is possible to share translation work during development but this makes the process more chaotic (which would be a nightmare considering the team has to work between two version of the game already)
I would love to see uniform release dates for all countries though.