I ran into this program today, while I was searching for something to create video based slideshows, DVD Slideshow GUI. I tried out the Video and FLV export and it turned out pretty nice. The UI isn’t that great but it’s pretty good. Of course you could also use Windows Movie Maker for videos, but again the UI isn’t great for that either.
Note: DVD slideshow GUI is a user interface for great free tools like Avisynth, Dvdauthor, HCenc, Media Player Classic, FFmpeg, Flvtool2, Mplex, Demux, mkisofs ect. and is coded in wxBasic. It comes as an installer with all the nessesary files included.