this is what IGN had to say about the new Dot Hack coming out in a couple years:

The proper unveiling of .hack//G.U. earlier this month brought with it news of another .hack game to be released prior to the first G.U. installment. The latest issue of Famitsu provides the first details on that game, .hack/fragment.

The .hack series takes place in a virtual Online world -- that is to say, they're Offline games whose story has Online themes. With .hack//fragment, Bandai and co-developers Cyber Connect 2 and Artdink are taking the series into the realm of true Online gameplay for the first time. Using a standard network adapter (no need for a hard disk) you'll have the option of adventuring alongside players throughout Japan (this is the Japanese version we're talking about -- the US version should allow for play against US-based gamers).
When playing Online, you first create your own character. You can give your character a name, profession and gender, and even modify its physical appearance. Once you have a character, you enter a lobby and search for two other players to join you on an adventure. Gameplay in .hack//fragment takes place in groups of three.
During offline play, you play along side two computer controlled characters. Bandai is pulling characters from the entire .hack series, including comics, anime and games, to appear as support characters. You'll be able to raise your own characters Offline and take them Online (let's hope Bandai has some security protocols in place to keep cheaters away).
Specifics on gameplay have yet to be revealed. The game is listed as a pure RPG, so we're not expecting the action-oriented gameplay of Phantasy Star Online. Online play is said to be similar to Offline play, except the characters that you adventure with are controlled by people.
Using Artdink's expertise in Online game's development, Bandai is promising a full-fledged Online experience. The game includes an Online interface that lets players chat, send e-mail and read news. You can even create guilds, which seem to be chat rooms exclusively for your friends.
Bandai will not be charging a monthly fee for playing, but there's a catch. While Bandai is setting up a matching server, actual gameplay takes place on an "area server," which runs on your own PC. Specific details on how the PC and PS2 will connect should follow in a future update.
Bandai is actually making this strange Online system into part of the game. Your PC represents a section of the .hack world, and using dungeon creation tools, you can create your own dungeons and areas. This is, of course, in addition to adventuring through the worlds that Bandai has created. There are a great deal of questions remaining regarding gameplay, security and hooking up to a PC, but if all goes well, .hack's first attempt at real Online gaming should be something to watch, especially for fans of the series. The game will hit Japan some time this year.