I just played clock.gmv.gz on my paperwhite using gmplay-1.5a from the first post. It works great!
Due to the increased screen size, the video has a white border above it and to the right.
The next version will center it and use a black border just like it now does for the DX and DXG.
I tried my version that plays the "noisy rhythms" sound demo while playing video, but it fails with "error while loading shared libraries: libasound.so.2: cannot open shared object file: No such file or directory", which is hardly surprising because the Paperwhite does not support sound (yet).
I plan to add two sound versions to the Paperwhite. One uses USB OTG with a USB sound stick ($0.99USD shipped from China eBay stores). The other method will PWM the power LED, so a photocell driving amplified speakers should work okay for sound output. I already tested driving the power LED using a script, but the best I could do is a 6500Hz square wave. I am hoping to go much faster using a C program. Even if we cannot go that fast, we can at least do synthesized "chiptunes" sound.