I think the 6.8 will be around for a while. I dont hunt or precision shoot. It seems like a good flat shooting round. I'm sure people with more experience than I will wring it out pretty good.
Want to know about the 6.8 SPC? Go to 68 Forums. A great bunch of guys over there.
As far as ammo goes, rumor has it that Federal is introducing some Fusion/Eagle type this year. That should add more to the market.
And here are your bullet choices.