I doubt there'll be any problems with that. It's not like you're gonna have hundreds of people running with you in a party like in WoW or whatever. I thought parties in FFXI were alot smaller than compared to other MMO's to begin with? I know MMO's can get pretty crowded though... but then my only MMO experiences really are Guild Wars and Ragnarok Online.
But yeah, of course our PC graphic cards today can out perform what a PS3 or even a 360 could do, but it's not like the jump in the graphical difference is that big of a deal really. FFXIV is gonna look pretty much the same whether you play it on a PS3 or a PC, although I'd imagine it would be alot easier to run on a PS3 because you never know what kind of jacked up requirements they might have, and you won't have to spend more on upgrading hardware to play.
Anyways, I signed up for the beta. I'm not expecting my new computer to be able to run it at all though. If I even get picked for beta. I never played XI... there were times when I wanted to try it, but I could never bother with it because I am extremely picky when it comes to the MMO genre.