Amazon has announced KF8 updates available for all Kindles post Gen2.  (DX is Gen2, sorry, sigh.)

Hopefully PG will be updating more of their books to KF8, but my understanding this is all catch-as-catch-can.

Also points out that if you want best reading results on a KF8-compatible Kindle perhaps your best bet is download the PG ePUB version and run that yourself through kindlegen v2.7

Unless Marcello has ended the dumbing-down in support of Mobi7 ?