Best of Breed or Single Vendor? Are fully modular systems feasible?

This panel will cover both the technology aspects and the business and contracting aspects of the perennial "best of breed' versus "single vendor" debate. All software products are modular on the inside but that doesn’t always mean it is feasible to mix and match modules from different sources. Is anyone achieving this today? Does anyone have a credible plan for achieving it in the OOSD world? What are the benefits in doing so? Do the incumbent PSS vendors have an unfair advantage in the industry move to Offers and Orders?