Martin Fowler has a great article on EnterpriseArchitecture in response to some criticism on his book. He highlights that enterprise architecture is all too often an initiative championed by IS rather than the business areas. It then has to take a backseat as an infrastructure project over other projects directly related to business value. I think this idea is key and really makes the point to identify business value and communicate it to the business areas if any project is to succeed.
I have had similar thoughts in some recent presentations and meetings, but Martin was able to eloquently sum up and communicate the idea!