For folks wondering about changes:
In the scenario team, one of our goals is increasing the number of scenarios run per year. To do that, some of the scenarios will be new designs or reworkings of or improvements on past scenarios, and some will be re-runs with little or no changes, drawing from scenario designs that have proven themselves to be popular and balanced.
BOB has been one of the most popular scenarios. Also, in BOB 2004 (whose rule set we are using this time around), victory/defeat came down to the last bomber of the last mission of the last frame -- so it is also a well-balanced design.
This scenario, slated to start late September, needs to be one that we can set up and run with little change so that we can fit it in before the Pearl Harbor scenario in December.