Crytek the owners of the Timesplitters IP currently have no plans for the franchise but that could change if they hear from the fans. They would need quite a bit of support and fans being very loud about wanting the series back.
Cevat Yerli said that while he loves the series no publishers want to pick up the franchise he would love to see the game up on their upcoming streaming service GFACE.
This also comes with Crytek turning to the free to play model after Crysis 3 is done, so in all likeliness any new Timesplitters would probably be free to play.
There is one current online petition to get Timesplitters back and that is on facebook and currently sitting at 20,000 likes check it out and like it if your one of the many fans who want the series back.
News Source (Eurogamer)