Every year or so I brush off my dusty Perl interpreter and mess a bit with AFT. I am not sure how relevant the system is these days. I still use it once in a while (I still resist using word processors).
I've been thinking about writing an AFT config/rule file to generate EPUB or MOBI formats for e-readers. I don't have a tablet or e-reader myself (yet -- ever?), but this looks like a useful exercise. I've also been thinking about standing up an online version of AFT where you can submit your files (or type them in) and generate HTML, PDF or EPUB/MOBI.
So much copious free time...yeah, right.