"movies" in the actual sense are unsupported currently.
What would be possible are animated splash screens, e.g. by showing instruments/MFDs etc.
That could be accomplished using Nasal, without too much work:
http://wiki.flightgear.org/Canvas_Devel ... sh_Screenssearch.php?st=0&sk=t&sd=d&sr=posts&keywords=canvas+splash++screenSupporting "movies" would be possible to, but would require C++ changes - e.g. to integrate OSG's support for video rendering with Canvas, and provide a dedicated video element:
http://wiki.flightgear.org/Canvas_Devel ... ew_ElementOne of the most popular feature requests is supporting video streaming, so that external live imagery can be fed into FG and used on displays (or scenery overlays) - this is something that UAV folks would like to do. Others would like to post-process FG imagery using OpenCV, which would require streaming FG imagery externally.
http://wiki.flightgear.org/Canvas_Devel ... ter_VisionIn other words, a splash screen video could be based on video streamed by Torsten's mongoose server to the Canvas system.
But for now, a simple animated Canvas-based splash would be fairly easy to do - e.g. you could show a PFD while shooting an ILS approach (outer marker, middle marker, inner marker) to visualize the completion of the boot process.
I would suggest that you make a proper feature request using the issue tracker:
https://sourceforge.net/p/flightgear/codetickets/However, in general, time would be better spent improving/optimizing the FG boot process than coming up with features to make the whole thing more "entertaining" - unless such features are orthogonal to other developments, e.g. Canvas elements that would be useful elsewhere