Persona 4 Arena was one of the rare cases of a PS3 game being region-locked. If I recall correctly, according to Atlus USA, their corporates in Japan issued the region-lock because they feared that they would lose profits from Japanese gamers (I think their biggest market) importing the cheaper US copies. I remember some controversy at the time with people fearing that this would lead to more Sony titles becoming region-locked.

Dude you are like what a year late to the party or what?

The European publisher Zen United has gotten some ridiculous flak over the course of last year since the game was delayed in Europe for almost a year. The fact that Atlus region locked even the digital version caused a huge storm like 6 months ago when it was released on PSN/XBL. So yeah man, you're definitely behind the times here.

That said, if you wanna play me sometime, holler at me. PSN ID is the same as my username. There's not many people playing the game online and would be nice to play with someone from here.

All the games I get are imports.

I don't follow gaming news past their announce dates nowadays for spoiler reasons, even fighting games i'd actually like to play them without knowing anything at all about them , so thats why. 

Did they announce anything about a patch or something to remove the region locking? since the game is old enough...

Funny enough I actually know about a Macross PS3 game that was "half region locked" as it was a game tie in inside the Blue movie.

but not this one

They locked it in fear of losing profits because the US version had Japanese voice-overs and was released very close to the Japanese version. Did the PSN store even have a warning for this?

Nope, no patches. Even the European version is region locked even after all the craziness. So yeah don't hope for the region lock to go away.