This will be one of the more interesting trends to watch next year. Based on how it has tended to go, it would be surprising if it started to go back down. The most likely outcome would probably be another small jump to 2.55, but we just don't know. A huge jump would almost certainly result in even fewer runs being scored next year (runs are down 10% from 4 years ago and 13% from 6 years ago).
Even if it jumps up in 2014, the long term trend will be worth watching. It might be that 2.50 is about as high as it could go for a full season, or various trends might mean that it is possible for them to get close to 3. If this trend continues into next year, then we'll see even less offense and great pitching dominance than we saw this year.