We know that Hitman 5 is in development, but it could be revealed in a playable form sooner than expected. Speculation suggests that it will be officially unveiled at E3 this year after a subtle marketing campaign.
The image above is an advertisement for Hitman-branded donuts with a barcode ending in "47." A Hitman forum user contacted the agency who placed the ad and received a response from a different email address that stated "you are on the right track."
The email also included the image below, which is apparently the script for a new Hitman game. The barcode in this image also ends in 47, and when when deciphered, forum users claim to leads to E3.