Being on PS3 and PS4 is good for this game's tournament scene, IMO. If a tournament doesn't have any other next-gen games early on, then they can use the PS3 version. Once more fighters come to PS4, the game can stay part of tournaments.
I guess I don't like the fact that the game's playerbase, as mentioned previously, could potentially be fractured by its release on two different platforms. If the PS4 version is superior, it would also be unfortunate for everyone to still flock to the PS3 version because most people will be playing there.