Gang Starr represent hiphop in its purest form. I have nothing but respect for this duo, they are one of the most consistent groups in hiphop.
But I seriously don't believe they will make another album. I want to believe, no doubt, but I won't count on it before it is confirmed, that they are working together again. Even though they don't make another album they will still leave a great legacy behind. If they do make an album they both better be 110% devoted to it, otherwise they should just quit while they're ahead IMO.