He'll appear in flashbacks on the forthcoming Darkside Chronicles, but his general role is still unclear generally apart from the established Canon plotline.(doubtful)
After Archives and Darkside Chronicles, the entire series is possibly going to be reebooted. If it is, Wesker may be reinstated into the new story, and I hope so, preferably with a larger role and not dying too soon this time. Either that, or a new villain will fill his shoes, which is HIGHLY unlikely. We'll have to wait and see.