Looks like there are plans for 3 Duke Nukem DS titles starting in 2009. The episodes will be entitled Critical Mass, Chain Reaction, and Proving Grounds.  Developer, Apogee, recently posted more details about these games, hopefully some screens will be released soon.

Apogee is bringing the King of Action himself, Duke Nukem, to the handheld console market with three new missions, together called the Duke Nukem Trilogy™. Apogee Software is producing the Trilogy under an exclusive license agreement with 3D Realms and MachineWorks Northwest LLC.  The Trilogy is comprised of three episodes: Critical Mass™, Chain Reaction™, and Proving Grounds™, with an engaging storyline that spans all three games. The episodes will being released sequentially, beginning in the summer of 2009. 

Features include:

• 9 Different World Locations
• 36 Action-Packed Levels
• 3D Accelerated Graphics
• 3D Characters with Detailed Textures
• Real-Time Particle and Lighting Effects
• Multi-Mode Play with up to 5 Different Styles of Game Play Action
• Multi-Player Action
• Total Ass-Kicking Weapons

Apogee is bringing its innovation to the handheld market by producing the Trilogy for both the Nintendo DS™ and Sony PSP™ utilizing the same storyline, but taking full advantage of each platforms strengths. This means a totally different gaming experience on each system while staying true to the storyline.