I like Play-Yan, but what it offers is really a step below the PSP's innate capabilities. The audio quality in my experience is not quite iPod-quality, and the video formatting requirements are in some ways just as fussy as the PSP's (for some reason, the "supported" 240x176 resolution runs horribly while the much larger 320x240 res is smoove as butter). On the other hand, 320x240 looks a hell of a lot better on the Micro's screen than stretched to fit the PSP's. And there are no weird file naming conventions or directory formatting requirements -- just drop everything in the top level directory of your SD card and the device sorts it out on its own.
As for import barriers: There are none. Nada. The interface is entirely icon-driven and extremely intuitive, and what tiny bits of text you can see are in English. As I'm a Mac user, I haven't tried the Media Stage software, but you don't really need it anyway as long as you have a decent video encoder like the open-source FFMPEG-X.
However, there are a few pitfalls you'll have to avoid. For one, you need some sort of SD card reader device to load files onto the thing; unlike the PSP, there's no USB port to connect directly to a PC. Oh, and don't use an SD card larger than 1 GB; I discovered the hard way that 2 GB cards don't work and have a really, really huge amount of memory available for my digital camera as a result. (I'm hoping the size limit is just a firmware issue.)
Anyway, it's a mixed bag. It's novel but hardly a must-have and you're probably better off waiting a few months to see if Nintendo of America finally realizes, gee, we could sell that too.
