Wii U won’t make Achievements Mandatory for all games.

[Mr Khan]

It seems to me like it would largely be a non-issue except for certain first-party Nintendo games, third party exclusives, and smaller games where Achievements have never been the right fit anyway

Think about it: with Achievements and Trophies in place, third parties running quick multiplats will have a selection of these sorts of things in place already, which they can slap a different name on and call it a day.