At the current state the system is still too slow to work with large AVI and MP4 videos, but it is already possible to play with animated GIFs (yes, the import of GIF files now enabled as well - thanks to Antonio Roberts for the hint! ^__^). Check the attached video for demonstration.
There is still a lot of room for optimization remaining and we will continue working on improving video import.
Also, we have made several improvements to default rendering export settings
We also improved our video export (rendering) options. Now the default output format is AVI (was PNG) and the codec is set to MPEG4 at 6000 kb/s (was H264 Lossless). Those settings should help most users to get their animations rendered with minimal effort. See discussion for details.
As usual, you can test all latest changes by building current Synfig code from source. We are working to provide you testing binary packages soon. Thank you for your incredible support and see you in next report!