I recently found the following on a web site:
In the new lobbies, cities, you can join up with people and quest together. This will throw you and your team into a instanced zone, with which you can do battle. It is not like a huge sprawling MMORPG world, it is infact more akin to the game style of Guild Wars' instanced missions, Diablo II's instanced areas (or 'rooms'), or City of Heroes' mission maps.
Each city can hold up to 1000 people, and multiple will exist per planet in the Gurhal system, to accommodate the PSU audience. The majority of party organization will take place in these areas.
The team concept has been radically revised for PSU. In PSO, teams were assembled in-game and only existed for the duration of the game. For PSU, teams are generally assembled in the lobby and last until they are desolved by the team leader. Teammates can commuincate with one another using Team Chat - even if they are on seperate planets. Also, teammates will be able to where everyone is at using an in-game menu option. Please note that teams do not have to be formed in the lobby, anyone that joins your game will automatically become a team member.
No PvP? No challenge mode? I believe I read that. Also, PC and PS2 users will play on the same servers. Xbox 360 users will play on a seperate server. The only thing I want to know is the cost per month, if any. Then I need to decide which system to play it on. I think it's safe to say my computer is out, it probably can't handle it.
This game, by far, is going to be totally awesome.