Blizzard has posted the preliminary notes for the next Diablo 3 patch. Among the changes incoming are the inclusion of a dueling ground, additional experience gains in Inferno level and new recipes for account-bound items.
We believe that Diablo shines when you can spend the majority of your time slaughtering hordes of enemies and then having that punctuated by the occasional difficulty spike either in the form of a particularly challenging set of normal monsters (like an elite pack) or a boss. With that in mind, what we want to do with Monster Power is set the reward so that there are incentives for playing at a higher level, but not make the incentives so powerful that players feel like they need to make the game less enjoyable in order to achieve a faster reward rate.
Read the full patch notes on the Diablo 3 community site.