I think an animation preview window should be implemented. This would pop up when someone tries to upload an animation, much like a texture preview window pops up when uploading a texture. This window would display the user's avatar (ideally, with all its attachments), provide a slider to determine the frame of the animation displayed (so you can view each frame individually before upload) and a play/pause button that allows you to play the animation as it would appear if it were played in-world.
This will assist developers in creating accurate and realistic animations that can be custom tailored for any type of avatar, no matter how much it deviates from the standard SL Poser 2 models.
==Chris
Edit:
Feature suggestion submitted as proposal #449