While I would love to have control over my remains (organ donation, science), I won't be around to fight or approve what my survivors choose. Still, for those atheists who decide now not to fight the religious wishes of their relatives, I can understand that. Burials are for the living. It's one of their mourning rituals. Who doesn't want to have their lives worth mourning over?
I'd like those that survive me to feed my body to scavengers. That probably won't fly though, so it will most likely come down to cremation.
When it comes to organ donation/ donating my body to science, I'm actually indifferent. I will sign whatever because I believe that life is for the living. After I die, I claim no further ownership over my body, so the living beings that remain can exercise their discretion on how to use the leftover meat and bones.