There will definitely be a RE6. RE5 did too well for there not to be one. When it will comeo out is anyone's guess...
I think a series reboot is a good idea. This whole Spencer/virus storyline has become long-winded and convoluted, IMO. Chris is 35 in RE5. In 5 years (which is about the time it'll take Capcom to create a new game anyway), he'll be 40. And Jill is right behind him. Why not introduce some young, new protagonists? The BSAA is a big organization... I'm sure they've got some new hires or graduates...
But, since they're basically restarting the series from from scrath with a rebeoot, they could re-use Chris and Jill if they wanted and make them whatever age they choose...