From what its written in THIS article, it could really become reality !

Gamecloud – What can you tell us about any sequels to Painkiller at this point?

Robert Stevenson – Good question, but we are under a spell of silence on the next adventure of Daniel Garner and a full on Painkiller 2 version. You never know when that might change though – definitely keep an eye out for some announcements about upcoming action in the world of Painkiller coming down the pipe!