The whole public-ledger setup of Bitcoin can lead to a technological arms race on mixing/tainting. Of course, tainting only works if it's done on an international level as otherwise there'll be a p2p market for swapping US-tainted coins for Russian-tainted coins.
Anyway, sounds like no-one is really interested in this. I suspected as such but I thought I'd throw it out there anyway.
Agreed, but it seems you are jumping the gun on the arms race. I think few people are going to care either way until "tainted" coins are not accepted by MtGox or people are getting prosecuted for dealing in certain coins. Doing "The Moral Thing" on our own volition is too hazy of a concept to do any of this sort of thing without overwhelming economic or governmental pressure. At that point we will start doing exactly what is required to appease those pressures, no more or less.