Who Owns Planescape: Torment?

This Direct2Drive Tweet may vex folks hoping that Planescape: Torment will be re-released in the current reissue-happy environment where older classics get new life via digital distributions. Word is: "@Daggity hah, would love to re-release Plancescape [sic]...if we could find someone who actually owns the rights! Sad." This highly regarded role-playing game was released in 1999, and developer Black Isle Studios closed in 2003, but publisher Interplay is still in operation, albeit tenuously, fighting to maintain control of rights to a Fallout MMOG. Presumably Interplay would have control of these rights, or would know where they currently reside, but one would also assume that Interplay would have been the first place the D2D folks would have inquired about this.