One of them was returned to service after 40 years in the boneyard in Arizona, back in 2011, I would expect they'll look at the other airframes there to see if they're suitable sources for a rebuild. Wouldn't be surprised if this is the end of this one though, it was already doing pretty well for a design that first flew in 1949 (the English Electric Canberra design that was then built by Martin)

It depends, but NASA has 2 more of these (currently under inspection, so not in flying condition). Given its importance, its most likely they will find a way to make it fly again.

That depends on a lot of factors. What is the damage, how much would it cost to repair, and is spending that much considered worthwhile by NASA or whoever owns it? (Or whoever buys it after this)