Browsing thru my email I ran across some info on a new .hack game, .hack//G.U.
The main site is here and some more info is available from IGN.com.
Also check .hack//AI buster a book from TOKYOPOP. Volume 1 is currently out, with Volume 2 out on 02/07/06. With Manga also from TOKYOPOP, check out .hack//Legend of the Twilight.