We already have the author's consent, actually (at least I think we do), and even a license for his Practical Dictionary of Chinese Medicine, but we've been terribly preoccupied with iPhone-related stuff and haven't gotten around to converting it yet; the Practical Dictionary is a very tricky title to convert because its entries are extremely long, in a funky format, and use some very fiddly tagging systems for references to other books and such. I'm actually kind of ashamed about it, we're normally a much better licensing partner than this and we've been putting them off for a really long time.
Though there's also a little bit of a business issue with a TCM dictionary, actually, and it concerns the "Complete" bundle. When Pleco 2.0 first launched, it actually didn't have a "Complete" bundle due to some licensing restrictions; sales improved considerably after we invested a lot of time and money in removing those restrictions, getting all of our 2.0 dictionary licenses to play nicely with each other and getting all of them integrated in the same "Complete" bundle. People really seem to like to be able to buy one thing and know that they have every available Pleco add-on at that time.
With a TCM dictionary, though, we end up in a bit of a quandary - do we include it in our Complete bundle, raising the price of that bundle and shelling out a lot of per-copy royalties for a dictionary that most Pleco users aren't likely to get much use out of (and some may even be slightly offended by, judging by a few of the emails I've gotten on the subject) for the sake of still being able to say that the bundle is "Complete," do we leave it out of the bundle, generating complaints from people who discover that it's not "complete," or do we get rid of the very successful "complete bundle" name / concept altogether?
For dictionaries that aren't quite so subject-specific - and I think Classical qualifies, as would a Chengyu or a character etymology dictionary - I think the first option of adding it to the bundle would be fine. We already include a modern Chinese-Chinese dictionary in the Complete bundle, after all, and even people who aren't learning Classical are probably going to encounter it at some point - e.g. when traveling with a non-Chinese-speaking friend / relative / etc, encountering a stone tablet / scroll / Ming vase with Classical Chinese written on it and being asked the inevitable "can you translate that?"
But TCM is a different case - if we offered a dozen different subject-specific dictionaries it might be easier, we could have a bundle that was "complete" for general-purpose use and a whole other "ultimate" or "super complete" bundle that included all of those subject-specific dictionaries - but with just one or two it's a lot harder to justify. We already have this situation with the C&T business dictionary, and to be honest I'm not sure we even made the right decision in that case putting it in the Complete bundle - business vocabulary may be a bit more general-purpose than TCM vocabulary but it's still something a lot of people aren't that interested in.