Great insight Lisa.  When we are in a new role I think we need to really listen to our gut.  It is only a matter of time before we absorb enough of the culture that we can get blinded ourselves.  People expect a new exec to make changes - there can be a "waiting for the other shoe to drop" kind of experience that can throw a monkey wrench into progress.

I also think that a new exec needs to move just as swiftly in building the team of aligned and committed leaders who is going to lead the company or organization into the future if they want to fuel momentum with their swift action.  People will be watching those they already trust to determine if the messages you are trying to send are for real.  Unless these leaders are reinforcing the messages you intended to send with your decisions (both openly and behind closed doors) in their actions and their words, inertia will set in.