I just looked up the troika site...
this is some of the info I got there...
Q: Where did the name Troika Games come from?
A: Its original meaning came into being back when Tim, Leonard and Jason were working on Fallout at Interplay. Their boss dubbed them ?The Troika?, and as they continue to work together to make great games, it seemed rather fitting to keep the name. As Troika strives to create innovative, quality games, it has taken on the additional meaning of Code, Art and Design, the three things Troika considers key to a great game
Q: Is Arcanum going to have a sequel?
A: We certainly hope so. As a first product, our publisher has decided to wait and see how it is received before they make plans to fund a sequel.
Q: What about Fallout 3?
A: The Fallout license is owned by Interplay, and they will make any sequels. Troika has no rights to the Fallout license and therefore cannot create games using the Fallout universe
so yes, they have plans for a sequel, but there\'s really not much to be said about it...