I realize that the new MBP 15" is not in the hands of anyone yet but would appreciate any thoughts on the likely trade off between processor speed and battery life. Specifically, what is the likely impact on battery life from moving from the 2.7GHz to 2.9Ghz i7 in the MBP 15"? After spending $3,300 on a 15" MBP 2.7"/1TB/4GB RP460, I thought it made sense to spend the extra $200 for the fastest processor (2.9Ghz). However, I'm trying understand whether the slight speed bump would make a significant difference to the battery life. My assumption is that at low load the battery life would be almost exactly the same. At high load, the 2.9Ghz would drain the battery faster but would complete tasks more quickly, leading to a small but relatively insignificant reduction in battery life. Any feedback and suggestions would be much appreciated!