Let's look at the field. Cancer is huge, of course. And gargantuan news coverage resulting from an AIDS-cancer merger would stir oodles of sympathy for its victims, and maybe even result in a mention in the Newsweek Conventional Wisdom feature, next to an arrow pointing upward. I expect that it would be tough to cut a deal with the cancer crowd. Let's move on.
Tuberculosis is resurgent.
AIDS could certainly latch onto TB's coattails for the ride. But TB has that musty old-fashioned patina about it, if you know what I mean. Maybe AIDS should not target only one disease for a merge. AIDS could start slowly, first picking up one or two afflictions that never get any publicity, then acquiring a few lower-profile syndromes and then slyly grabbing a pox or two while the CDC isn't looking. In the second half, just after a Viagra piece.