But he does say that there will be no more new level 70 rewards, so what's out there right now is what you get. What we still don't know is whether Arena points from level 70 will carry over into the level 80 bracket, or whether there will be a complete reset of all the ratings and totals for the new bracket. There are good arguments for both sides (some players want a fresh start, while others don't want their winnings so far to count for nothing), but so far we haven't heard anything official yet.
So there are still a few things for Blizzard to decide with the higher level Arena system, but they've got time -- it's unlikely that they'll make people rush to 80 just to get involved in the Arena. It seems that when these next ten levels of content come out, Blizzard will switch some focus back to PvE and battleground PvP rather than the Arena game.