Here is Federal Computer Week's article on project management in the states. What the article doesn't do is explain how to identify, budget, and prioritize projects within the enterprise. Who determines what is important and how do the important things get funded? Ernie Neilson's model presents some great ideas for assuring that project managers and employees understand how their project interacts with enterprise objectives.
The "theory of conscious alignment" seems to recognize that agencies within a larger organization are undergoing some sort of process to assure that individual goals are aligned with and prioritized within the structure of the larger enterprise. This seems to be a difficult venture for any sort of enterprise, but for government in particular where agencies often perceive their mission to be unique and independent, although IT clearly presents an opportunity to provide linkages, integration, efficiency, security, and improved service if component parts can begin to understand what it is that they have in common.
IBM presents their version in Fusing business and technology