Considering Sony is involved with this now (why else is there a PS4 version? Sony must have made a deal with Sega and Atlus for them funding a port for the PS4), I see this being a multi-regional release ala Pokemon X and Y.
Sony is making the PS4 version while Atlus/Sega/Persona Team is making the PS3 version, so they will have the Atlus Translation team working right alongside the PS3 team to get a English version up and running by the time both versions launch

.
I don't think English Voice actors will be in the base release (despite that being the case for P3 and P4) if this is a multi-regonal release (with them being added a month or two latter via Patch/Free DLC) as they will need more time to get the voices recorded.
Sony must see this as a huge game (rightfully so

; P4G did wonders for the Vita in JP), so they WILL make sure Atlus and Sega have everything they need for an English version to be ready alongside the Japan version

.