dothackers.net

It is an offline and online game. It is going to be on both PS2 and PC. In the offline mode, you play as a pre-made character named Ethan Waber, a 17 year old cadet who is on a quest to rescue his 13-year old sister, Lumia from an
alien force known as the SEED. In the online mode, you create your own character using male or female versions of the following races:Hume(Human), Newman, Cast(Andriod), and Beast. The maximum party members you can have are 6, including yourself. You create your own robot and buy them parts. Thay can also be fighting monsters if they are in your party. The robots will be replacing the MAGs. To play the online mode,
you have to pay $13 per month to get to play online.

As far as I know there's no information about the monthly fee, nor if there will be one (but there might be considering the PSO series, which PSU is the sequel of, had a fee to play online) nor about the party member maximum, but I could be mistaken.

Regardless of that, I'll be getting the PC version, mostly because my friends will be getting that one too.
Of course, there's always the possibility that the PC and the PS2 versions can play together, but just in case, we're all getting the PC version.

I am voting for PS2 version. The fee is most likely $13 because it said it would be $13 in a Gamespy preview.