I doubt there will be any release of The Hobbit in 48fps. for home media, at least for many years.
The Hobbit will only be released in 48fps~3D for those cinemas that have invested in a new HFR(high frame rate) DCP server. (about $10000)
The rest (majority) will get the movie in 24fps, both in 2D and 3D.
The Cinemacon showing was the first for many things that people had not experienced which might have been as important to the experience as the HFR.
Shot and post produced in 4K digital with slightly higher shutterspeed than normal.
Shot with more depth of field than Avatar.
Dual 4K projectors.
3D in 4K resolution for both eyes.
Silver screen that was calibrated for the light at the edge of the screen and equalised brightness uniformity towards the middle. (silver screens are notoriously brightest in the middle)
Equal brightness to a 2D screening.http://www.dcinematoday.com/dc/pr.aspx?newsID=2784http://www.dcinematoday.com/dc/PR.aspx?newsID=2763
So for those that really want to see the Hobbit the way it is intended to be seen, they have to take care to visit a cinema that have dual 4K projection. Preferable with Christie or Barco DLP projectors if the screen is large (DLP sharpness is better than Lcos (Sony) on a large screen).