FFXIV has not had a chat client for 1.0 and beta. I have yet to play an MMO with its own voice chat system, so I don't know how common of a practice is it.
For PC, it is assumed PC players will set up their own chat groups, if desired.
I don't have a PS3, but I assume the system has some form of group chat? If so, that would be your only option.
I know how useful voice chat can be (my FFXI group uses it frequently), but since not everyone likes using voice, I believe SE recognized this and wanted to develop a game that would not require it. I do not remember them ever responding to questions about voice chat, so it might not have come up, but I don't browse the forums constantly either.
The devs have so far been pretty receptive to feedback, so you could comment it on the feed back sections of the beta forums and they'll probably give a reply one way or the other, with their reasoning. It would be nice to have cross-platform chat, however.
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