Some friends and I have been bouncing this idea around for years. If one of the main things we are going to use bombers for now is launching cruise missiles from very long standoff distances -- ie, nowhere near the bad guys -- all you really need is something with a LOT of payload.

With some reasonable assumptions about how the mods might be done, you can put something like 2 or 4 times the missile load on a 747 as a B-52, I don't have the back of my envelope handy right now.

Useful even over enemy territory. In Afghanistan the B52s sat up at 40,000 feet, flying around in lazy figure 8s, contrails clear as could be in the daylight, because there was nothing to shoot at them. If what you want is a truck to unload JDAMs or other munitions, just put a bomb-bay door in a 747 cargo jet.

Best of all, since lots of the bomber pilots are reservists who fly commercial, it means you can piggyback on the training and experience those line pilots get every day!

If you resisted the urge to gold-plate the thing, you could probably get 10 B-747s for every B-2 Stealth bomber (with something like 50 times the payload).

It may sound crazy but we actually found a Boeing study on doing exactly this from the mid-80s. Of course the fact that Boeing advocated it doesn't mean it's not crazy, but at least real airplane designers have fallen for the same crazy idea.