I think the word reboot is being misused too often. Wouldn't they just recast Indy? A reboot means they throw out the old continuity and set the new stuff in a new ficitional universe set apart from what came before. Let's say they recast Indy and set these films before, between, and after the movies we already have. Are they going to pretend Shorty, Willie, Marion, and Elsa aren't characters? Did Indy never find the Ark, the Sankara Stones, the Grail, or the Crystal Skull? If not, then it's a reboot. But otherwise it's just a recast.
I'm opposed to both to be honest but I guess a recast would be better than a reboot.