A Neogaf user that goes by Quirah says that the Eurasian Software Market Manager Sercan Sulun mentioned that a sequel to The Last of Us is not ready and shouldn't be anytime soon.
"There is no information about a new The Last of Us game but I can share this knowledge; as of this summer, The Last of Us will be on the PS4. Both on PSN and physically."
"The PS4 version will also include the DLC so you will be able to play 'Left Behind' as well."
Sulun has been a prominent employee of Sony since August 2012, so there should be truth to what he is claiming.
Would you want TLOU for the PS4? Comment below.