Larian Studios Forums Divine Divinity (English) Technical Problems Raze...a little bit of help here

Check the Announcements forum; there are links to a couple of interviews with a bit more information than in the Riftrunner FAQ.

Riftrunner is set 20 years after Divinity and there is some overlap with places and characters, but I think it is more of an independent game (set in the same universe) than a sequel.