"I firmly believe the B-52 and 707 will both make the 100 year mark."
Another sad example of how we're cannibalizing the past for the moment. It's a common theme in Obama's America.
Actually, the B-52 was already programmed to fly through 2034, and that happened while GWB was President. Both it and the 707-300 (which is what J-STARS is based on) remain designs of unmatched strength and versatility. None of the later airline designs, by Boeing or anyone else for that matter, will ever fly as long as the 707 has. And as far as the B-52 goes, yes there will be lots of high tech gee whiz stuff created - but they will replace the B-1 and B-2.
As long as there are nut-ball crazies riding around in pick-up trucks with RPGs, we will need some large, slow, dependable aircraft to drop iron bombs on them. Many have been designed to supplant the BUFF, they are all gone.