People are really missing the elephant in the room here. All this talk about hardware and how it has any influence over a portable version of either FFXI or FFXIV is completely beside the point. It doesn't matter. What matters is how users expect to use the device, and how games and software make sure to conform to the users needs when using such a device. Hence the number of polygons or amount of memory is not the issue. The issue is that the Vita, like a Smartphone, is going to played on-the-go. While waiting in line, taking a bus, etc. It's not likely going to be exclusively played at home where an existing infrasturcture already exists.

For example, in order to properly function, games will need to power down when the user puts the unit in sleep mode, for example. This can be done at any moment at any time. How are games like FFXIV and FFXI supposed to handle such situations? Obviously it would require the user to spontaniously disconnect from the game. This would be considered unacceptable by the player base. And hence would kill any such version of the game.

So no FFXI or FFXIV for the PS Vita. No port for the iPhone or Android either. Best you might see is a gateway or communication tool to grasp a snapshot of what's going on, but even this I don't beleve is likely.