It would be nice, especially with the soulbound stuff (I presume I will someday have an alt coming up through Outland that might need some help), for Blizzard to give us an out. Even if it requires level 80 to do, and even if the exchange rate is terrible (something like one level 80 badge for five or ten level 70 badges), at least we'll be able to get rid of the old stuff. Obviously, they're worried that if they offer exchanges for new items, people will go back and grind the old instances for the old currency. But there has to be some middle ground or a level requirement or something, some rate that allows us to get something for the old junk, while keeping current level 80s from exploiting the system. Heck, even cloth has a reputation turn-in value, at the very minimum.
The Stone Keeper's Shards at least have a turn-in for honor, and at the bare minimum, that's what you'd want for any currency -- something cheap that you can just cash out of the system with all of your leftovers. Blizzard may say what's past is past (and like I said, I may just need to spend a weekend cleaning out the bank), but it would be nice to have an NPC in Shattrath that can say "Oh, you're level 80? Let me just take those old tokens off your hands at a discounted price!" And it would be an Ethereal, of course.