So when in October will this be happening? It's still ambiguous, although dates are due to be announced in June. But it's definitely happening in October, and it's definitely going to be in Vegas. This also counts as the inaugural festival for the game, as previous years simply incorporated coverage of FFXIV into the FFXI fan festivals. If you can't get enough of chocobos and moogles, you'd better start saving your money now; the full press release is available after the break.
[Source: Square-Enix press release]