I have hughes net and was getting a 360 tommorow, I seen that Vana'diel collection comes out tommorow as well and am planning on picking that up. Anyone have an idea of how bad it will lag? I know its gunna be bad but how bad can it be really?

I play FFXI on satellite internet on my PS2, the only thing I had to do to keep my connection stable was set my PS2 in the DMZ of my router. Whether or not you have to do that I'm not sure, as my ISP is different (I'm Canadian.)
I do notice a slight lag when casting spells, although I can still out-stun a BLM (which means the lag isn't that bad) and when I ride a chocobo I tend to appear as "teleporting," and view other chocobos as "teleporting," across the screen.

Other than a few casting time reductions and the chocobo issue, everything else seems to run smoothly. Just be sure that the required ports are open in your router (they can be found at the PlayOnline (http://www.playonline.com) website.)

Large group activities such as beseiged lag, but those lag on everything. Despite the lag there, I always get full experience and can attack and cast and use items efficiently enough.

Basically the satellite internet shouldn't be a huge issue, providing you don't get randomly FAP'd.