I believe that whether or not it is internal or external is really up to Matt in the end.
I have to admit tearing into all this is a bit beyond me but I have been working at integrating whoosh into a desktop app to index epubs and make them searchable. As such I have been looking for something like this but really there is nothing out there. There are little bits of code here and there but all part of much larger projects and all tied to one web framework or another. So far in my case none of this is much help.
I am using pyqt and webkit and intercepting all the calls so there is no webserver involved at all. In this use case it is a simple matter of parsing my data sending it through the temaplating engine and then writing it out directly to webkit mainwindow html.
I have been searching for something simple that has ajax support so I can make my html forms a little more dynamic but do far I have not found anything like this.
In the instance of what you are building It would be great if there was the api but not necessarily tied to a specific display type. That way if using a traditional gui then no issue if using a webgui then no issue in either case just plugin the way you want to display the data and you have a good solution.
So far Whoosh is wonderful and is a really helpful bit of code that saved me tons of work.
I hope to see the results of your hard work and I hope that it is a wonderful contribution also.
Thanks
Brook