Frank Patrick wrote an excellent article about the importance of tying project management to the organization strategy. This also reflects strongly the opinions expressed in Kendall & Rollin's Advanced Project Portfolio Management and the PMO (project management office) that I reviewed.
An effective strategic roadmap serves several purposes. It identifies the things that are currently blocking desired levels of attainment of "goal stuff" and tactical objectives designed to get there. Once short- or mid-term problems or blockages are dealt with, the strategic roadmap also lays out a clear vision that builds upon the future freed up capabilities and defines the path to strategic objectives.