Even though it's the last FF title on the PS2 doesen't mean that it'll come out that early, take Kingdom Hearts 2 for example, it come's out March in the US, but here in the UK we get it Summer 2006. FFXII is supposed to come out around August in America, but since it's Square-Enix were talking about, i wouldn't be suprised if it came out May and was on the PS3.
I'm not buying FFXII anyway, i think Square were stupid in taking out the world map and Random Encounter's, meaning it'll be really easy to Do a Low-Level game now. :P