According to NHK news, from April JL will offer a new, first class seat on some domestic routes for about 10 000 yen extra. These would most likely be on main routes such has Haneda (HND) to Sapporo (CTS) and Fukuoka (FUK). Seats look great! (Sorry no pic to link). Also a better service (food?) will be offered.
Other points from the report: average age of NH fleet is 9 years compared to 11 for JL. NH has increased market share on domestic Japan routes. JL will cut 4300 jobs.