WTF is this shit? Why is this an issue? You're really arguing about a hard fork for a few millionths of a BTC? Trivial much?!
By the time we get to mining fractions of a BTC per block, TX fees will more than likely offer enough incentive for miners to keep hashing.
I already answered this question but the short review is that, if it were the case that optimistically high BTC value made it so that .5 satoshi was indeed a mining incentive, by definition it would also be the case that transaction fees tolerable by users would be orders of magnitude beneath 1 satoshi. Ie insufficient mining incentive would only be a problem if it became a problem.
Currently the block reward and transaction fees stabilize each other.
Thanks again Moon, kjj, and retep.