I've seen that Nintendo are publishing this in some regions but that Atlus are handling it in others. Does anyone with more information/knowledge about Persona have an idea if this could see a release on the Vita or should I just go buy one of those new 3DS's when they come out?

I'd say that it'll remain a 3ds exclusive, Nintendo is helping out and wouldn't want it on another system if they do.

I feel like the process to convert from 3DS to Vita would be pretty tedious. No knowledge about it just a hunch. Are there other games that have been ported?

I wouldn't count on it regardless, I assume Nintendo would want to lock that up on it's mobile platform.

Thatll mean that they will have to port the Etrian Odyssey engine to the Vita as that series only came out for DS/3DS

Atlus doesn't do multiplatform releases very often and I don't see a siginificant financial benefit to porting it to the Vita, given the amount of extra effort that would be required. I'm pretty confident that it will stay 3DS exclusive forever.

The way the Etrian Odyssey series works, specifically the mapping mechanic, means it only makes sense on a system with 2 screens.

I can think of some ways that Etrian Odyssey's mapping could work on the Vita but all of them are kinda clunky compared to the 3DS version.

Shin Megami Tensei IV would probably be a better fit on the Vita, but I doubt that one will happen either.

I'm gonna say a huge No to that. Etrian and PQ heavily rely on drawing maps with the stylus. You can't pinpoint like that with your finger on the Vita's screen.

It doesn't seem like Atlus has the resources to do multiplatform development, unless that is a stated goal from the very beginning (Catherine was always going to be a multiplatform release, because they wanted to familiarize themselves with the consoles so they could also make P5 a multiplatform release, though in typical Atlus fashion this process has taken them like 6+ years).

The only time they've done "multiplatform" releases besides that is when they port old-ass Saturn/PS1/PS2 games to newer platforms (Persona 3 and 4, SMT: Devil Summoner: Soul Hackers, etc.), but it seems like that's about the best you can expect. Persona 3 and 4 ports make sense because those games have a fairly large cult following, but the Soul Hackers port was fucking bizarre. Anyway, the weird spinoffs like Persona Q and the dancing game on the Vita seem like side projects that Atlus probably knows won't be huge moneymakers, so I can't imagine them bothering to port those games to other systems.

If you want to play Persona Q, you should probably buy a (new) 3DS.

Thanks for the responses guys. Looks like I'll be looking at a 3DS sometime next year.