A few people touched on it, but there is quite a difference between playback at 48 fps and recording at any other speed. If I read somewhere correctly a while back, the Hobbit was shot mostly at 4k 96 fps. This gives them the option in post to slow things down with incredible detail. The RED cameras that they are using are absolutely amazing. I was in a short video shot on a RED EPIC last summer and it was better than anything I could have imagined.Super Mario Marathon 4 : Boredom is in Another Castle!
I also watched a live stream of some video people who were filming a light bulb being smashed. They were shooting at 120 fps, and they were not able to actually capture the glass cracking. I think they estimated they would need something in the 500-1000 fps in order to capture the glass cracking. More fps is like having more resolution, except not in pixels, but in time.
We are all "used" to 24 fps in the theater, and 30 fps on TV. Once we become accustomed to 48 fps, it may not be such a big deal. If it looks anything like the "enhanced" modes that modern TVs have, though, I will probably hate it too. I always turn that crap off because I think it looks like campy pan and scan.