There's a Mike Verdu interview on gameplex talking with the designer and producer for Unreal II, the upcoming Unreal sequel in the works at Legend Entertainment. The conversation (also available in the site's original German) covers a lot of general background for the game, the following clip provides Mike's answer to the question about how directly the follow-up will follow on the storyline of the original:

Unreal II is a sequel to the original Unreal and takes place in the same universe - but you take the role of a new player character and travel to many new worlds. You are a Colonial Authority Frontier Marshal charged with the safety of scientists, colonists, terraformers, and miners in a sector of space that is just being colonized. A war breaks out in your patrol area and you must protect the civilians while you work to discover the source of the conflict and attempt to stop the fighting.