From a couple of sources we have bits and pieces that suggest the Lab is looking to provide a built in viewer feature for handling avatar animation. Currently we use animation overriders (AO) to override the built-in avatar animations. Most of those are a HUD of some type.

Discussion is in progress to determine what AO feature set is needed for the Lab’s viewer. Since AO’s are basically free (only the animations cost) the user’s choice of which one to use is entirely based on features and personal preferences. Free market principals allow the best to become the most popular.
Concern is voiced by some that a built-in replacement for AO’s by the Lab may limit our freedom of choice. However such limiting would break a considerable amount of existing content. Breaking all the existing AO’s, or any content, is something the Lab is loath to do. So, I can’t image the Lab will take that path. Whatever they do, will allow users to still use their AO’s.