Yeah my reaction was the same. From "what?" to "ah online - NEXT!"
This won't be as big as FFXIII. FFXI on the Xbox360 did poorly and so will FF14. Besides I doubt it will be exclusive, since Square Enix said they are checking other platforms as well, including Microsofts.
I know there is a huge Final Fantasy Fanbase, but with FFXIII and FFvXIII, there is 1 major title and a spin-off already out in 2010. A third FF just for the online won't have a huge impact. So far, there is no MMO-game on a console you could call a great success like the ones on the PC.
Imagine not having GamePass on your console...