Yes, there was a Hitman movie back in 2007 starring Timothy Olyphant. No, this is not a sequel, the franchise is already being rebooted. The only thing being retained from the previous movie is the screenwriters, everything else is new. Originally Paul Walker was going to play the Hitman, but after his untimely death the role was given to Rupert Friend, aka Peter Quinn from Homeland. Walker would have been great, but I think Friend is a good fit for 47 too. We'll see sometime in the future, I suppose.
Additional cast members have been added to the fold, including Zachary Quinto (Star Trek) as John Smith, Hannah Ware as Katia van Dees, Thomas Kretschmann as Le Clerq, and Emilio Rivera as Fabian. Agent 47 will stealthily creep into theaters on February 27, 2015.