PM sent.
The complete story of the Japanese subs is scattered over many posts in this thread, so I guess I'll collect them all in one spot.
First off, I always recommend graphical subtitles over SRT files. SRT files have the advantage of being small, but you lose the font, size, positioning, and layout information you get with the graphical subtitles. Even once we finally have Japanese SRT files for ROTJ, I wouldn't recommend anyone actually use them, but instead use the new graphical files derived from them.
That said, the current graphical files for ROTJ are upscaled SD-quality graphics, so they are not as sharp as the others, and they do look a little dated. We have OCR software that can turn pretty much any graphical subtitle into equivalent text, but with many errors requiring manual correction. We have had a project going on called Operation Eyestrain in which people are going through the files that have non-Western characters and manually correcting them character-by-character, usually not knowing the language in question (Arabic, Thai, Chinese, Hebrew), and in one special case, by someone who actually knows the language in question (Japanese).
Japanese is special in a few ways. First off, the original GOUT-based Japanese subs make heavy use of Furigana, which is something that can't be copied in a usable fashion directly into a text file. You could leave the Furigana out, of course, but that often leaves you with a pretty inadequate translation. Also, there are some translation problems in the files themselves--for example, Return of the Jedi is translated as Revenge of the Jedi--historically interesting but not really a good translation.
For that reason, the Japanese SRT files aren't just a direct transcription of the GOUT subtitles, but are instead a re-translation, using the GOUT subtitles as a template. I'm really quite happy with the work our translator has done on the first two movies, and I'm willing to wait to get subtitles from the same translator, making the same stylistic choices, etc, for the best consistency between films. Right now, our translator is crazy busy with real life stuff, but still willing and able to do the job. Since I have no real deadline other than Harmy's next ROTJ release, I'm happy to wait some more.
That said, if things go sideways and our original translator can't do it anymore, I am keeping a mental tally of other offers for help ;)