It works :) Trial only works for vanilla no matter what system. That part is in the FAQ. I do have all the expansions up to Wings of the Godess on PS2 though :p was rough finding the last two and I bought them in 2008, so you'd probably have to get them used now. I hope they don't pull this kind of "oops, we're not supporting that platform anymore" junk with the PS3 verison of FFXIV... Anyway, I'll post back in a few minutes to let you know what my trial character name is.
Edit: ... and by "a few minutes", of course, I mean a few minutes after I take a few hours to download all the updates I've missed since November 2008 xD