I will just post my answer from the other threads about this topic: Games that NEED a sequel [http://www.escapistmagazine.com/forums/read/9.115482] (same title, different thread):
What's worse than games that absolutely need a sequel (Planescape 2, I'm eyeing you!) is when a sequel was actually being worked on but then canceled.
Take for instance Dungeon Keeper 3 [http://en.wikipedia.org/wiki/Dungeon_Keeper_3]:
A third episode of the Dungeon Keeper saga was underway, but opportunities to develop new intellectual properties on new platforms such as PlayStation 2 have meant that DK3 has been put on hold. [...] The projects that provoked Dungeon Keeper 3's cancellation were EA's Harry Potter and Lord of the Rings games.
So we lost DK3 because someone thought it was more important to release a Harry Potter game... That's just sad. Seriously.
Another great loss is the sequel to Stonekeep [http://en.wikipedia.org/wiki/Stonekeep], Interplay's 1995 RPG:
Interplay's own Black Isle Studios worked on a sequel called Stonekeep 2: Godmaker for five years before cancelling it in 2001.
Five years... As far as I can see there were no screenshots released and there was no reason given why it ever got cancelled.
And a sequel for the astounding Arcanum [http://en.wikipedia.org/wiki/Arcanum:_Of_Steamworks_and_Magick_Obscura]:
In September 2006, one of Arcanum's lead programmers and tri-founder of Troika, Leonard Boyarsky, divulged that the studio had originally commenced work on a sequel, going by the working title of Journey to the Centre of Arcanum, which would use Valve's Source Engine. Development was curtailed by disputes between Sierra and Valve, resulting ultimately in the project being shelved.
So it appears that no news means good news in the art of game sequels, so my hopes for Planescape 2 are really high now...
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