As probably you know, Kyushu Shinkansen will be opened all section between Hakata and Kagoshima-Chuo on Mar 12, 2011. JR Kyushu released the tentative schedule. You can see the timetable here(PDF).
But this timetable is only in Japanese. So I made some sample timetable with Japanese-English translation. Before you take a look at the timetable, please click this image.
This timetable consists of 4 page as PDF file. Each page has two directions. The top half of the page is the timetable for Shin-Osaka to Kagoshima-Chuo via Hiroshima, Hakata and Kumamoto. The bottom half is the timetable for Kagoshima-Chuo to Shin-Osaka via Kumamoto, Hakata and Hiroshima.
We will have four round trips for the fastest train, “Mizuho”. We will have Mizuho or Sakura mostly once an hour between Shin-Osaka and Kaghoshima-Chuo. It takes 3 hours and 46 minutes by Mizuho from Shin-Osaka to Kagoshima-Chuo. It takes about 4 hours to 4 hours 30 minutes by Sakura between Shin-Osaka and Hakata.
We will have four departures an hour between Hakata and Kumamoto, and two departures between Hakata and Kagoshima-Chuo.
Unfortunately JR Group did not announce anything about Japan Rail Pass validity to take these new trains, Mizuho and Sakura. I will let you know right after I get an information.