Very interesting.
If you are interested in making this happen, development instructions are here:
http://manual.calibre-ebook.com/develop.html
Also, future notice: Best to discuss these things in the
Calibre forum here, specifically the
Development subforum. (A moderator should be along shortly to re-file this thread.
)
Then Kovid Goyal can see this, and hopefully indicate his willingness to accept any changes along these lines (best to double-check in cases like this,that there aren't any pre-existing plans).