"Pundita, re your 'Perdition' essays:
Your cautions re Bill Gates et al's ‘programs’ are well taken. In any complex system -- and human societies are among the more complex ones around -- there are always emergent phenomena which are evident only under the correct conditions. Ergo, change the conditions and new, previously unsuspected, phenomena emerge. Sometimes it's a pleasant surprise....
One thing we always do (or, ahem, always ought to do) in networking is have a plan in place -- in advance -- on how we're going to roll back the changes we just made if things don't go quite as well as expected. We find it necessary more often than we'd like, because none of us are prophets in our own times.
How do you roll back the eradication of a disease which held populations to a level that could barely be supported by the local conditions? Make way for at least one of the Four Horsemen: War, Famine, Pestilence, Death.
It all comes down to being very, very careful what you wish for. And thinking really hard about what things will be like if you get it.