... is there any interest out there in a general-purpose JS/Ajax library specifically for Domino?
It is my intention to release such a library into the wild. The library itself will be free to use anywhere, both as in speech and as in beer. Thanks to View->Source and browser extensions, there's no good way around that. Even if the code is obfuscated (and it is, has been, and will continue to be, for compactness' sake), a determined developer can copy it and find a way to use it. The API documentation, though, I can charge for, so I will. Or, rather, somebody will.
The documentation will include the clear, unobfuscated code with comments. While the clear code would be entirely impractical as a user download (it is not a little file, or even a bunch of little files), forcing an interested developer to figure out which bits do what in the obfuscated code alone is not going to result in better code or in a better developer. Properly done, this might make a good addition to a certain training materials package, since the doco is as much about "why" as "what".
You see, I'd like to see this, or something not unlike it, become a standard part of the Domino developer's toolkit. While I would like to see every developer equipped with the knowledge and skills to do all of the work themselves, it just doesn't make sense that each of us needs to reinvent the wheel with every new application. Okay, the truth is that I was tired of reinventing wheels by the third go-around. So I've taken the bits and pieces of what I've been doing over the last year or so, located the reusable bits (and refactored to include them where they'd been redone), and come up with something I think is worth sharing. But I know that I've only included features that I needed at the time, and that there have to be things you might think are commonplace that have never occurred to me.
So if you can think of anything you'd like to see, anything that can help you elevate a garden-variety web-enabled database to a holy-crap-gotta-have-it application with minimum effort, let me know. Your suggestion may be what makes the whole thing worthwhile.