Well they tried doing Alien Breed, but it seems no one were too keen on playing them. And then Alien Swarm was released which was pretty much what people wanted in a new Alien Breed game, only free.
Honestly, I felt that the old games are still better. The new ones just didn't click with me; I only tried the demos. They look nice, but somehow the fun level is off. I was very happy when GOG re-released the DOS versions.