I see the opportunity here as a “yes and …” opportunity. I agree with the posts above offering that the integration be led by a full time, highly qualified leader. While the integration work is underway, the business is expected to run well and achieve defined business outcomes (I can’t bring myself to use the term “business as usual” as I believe it often connotates work that is lacking agility and forward-thinking). I don’t think either workstream can run with blinders on. I see them as sharing mutual accountability for goals at the top of the organization… they have different pathways, expectations and metrics to deliver those org level goals. Eventually these pathways will converge so it is critical that there are some formal and informal communication loops between the business that is still charging ahead and the integration effort. Yes, we need the business engine to keep churning and delivering AND we need the integration work to hit the milestones and deliver. Communication and collaborative forward-thinking infused into the day to day work for the “BAU” and the integration work are game-changing elements.