[wladimir]

Those formats aren't really dead. Just that the web browsers don't support them doesn't mean they're not used.

mng is currently used for simple animations in UIs (for example, Qt has built-in support for it). On the web, I guess there just isn't that much of a need for an animated format (other than fully-fledged movies).

jpeg2000 is used by some 3d tools and games as texture/asset format.

WEBP already has the advantage that it has been implemented by one of the larger browsers, and that it supports everything. Lossy, lossless, transparency, animation. And smaller files as a bonus. It could be the image format to end all image formats :-) I can see a lot of uses outside the browser as well, even if it fails as browser format. I also think google is going to push it as the defacto image format for Android.

Support in design tools isn't that important. One can always convert image formats as part of deployment. In many cases this is needed anyway (for example for CSS spriting / inlining).