Personally, I don't think whether DSLR is around in 10 years matters that much. If DSLR is dead, then it's because something superior has replaced it.
But what I think we can be pretty sure of, is that in 10 years there will still be bodies/sensors that can take EF lenses.
We as Canon's customers have far too much invested in EF lenses to be interested in giving up the EF mount lenses on such a (relatively) short term horizon. Canon knows this, and will make sure that we are not overly tempted to abandon them (ie jump ship to, say, Nikon).