Of course there's going to be a Resident Evil 6! Resident Evil: Retribution made over $221 million worldwide, and the franchise is still going strong. They're going to milk it for all it's worth. Director Paul W.S. Anderson has also previously said that he mapped out the franchise through a sixth film.
STYD is reporting that Sony Pictures and Screen Gems have set the release date for the film for September 12, 2014. If that's the case it looks like Anderson and Milla Jovovich will have to start shooting the new film this fall.
The sixth film doesn't have a title, and there's no story details, but the last time we saw Alice, she ended up at the White House facing down a crazy threat with Wesker by her side. Unfortunately I haven't really cared for the last few films in the franchise. They just seem to be getting progressively worse. I'm kind of hoping this will be the last film in the franchise, but chances are they'll end up rebooting it eventually.
Source: STYD (http://www.shocktillyoudrop.com/news/172723-sony-sets-a-release-date-for-resident-evil-6)