Update on Final Fantasy XIV Online:
G4 reports from the Square Press Conference that the game will have solo content at launch. The devs confirm that they "want to make it so the player can choose to play solo, in a party, 40 minutes, all-day... there will be content for ALL of those play styles and systems for all of those play styles".
Guess that answers that question.
No word yet on the game's job system, pricing (a monthly fee is probably a safe bet), or beta/launch schedules (other than the original announcement that the game will arrive next year).
They do confirm another absolute no-brainer, that they will NOT offer character transfers from the current game to the new one. Interestingly, they comment that, even though the game is set in a different world (FF games almost always are), they went out of their way to make the races look visually similar so that players would find them familiar. I guess that could be somewhat comforting, though I'm not sure that I wouldn't choose to make a clean break with a totally different look if one of my current games does go to a sequel.
Finally, the game's trailer is available - apparently some of the fight scene on the boat was actually done with the game's engine, in which case we can expect a moderately pretty game.