NEW YORK (AdAge.com) -- It will be at least nine months -- and probably closer to a year -- before Microsoft takes over Yahoo's search infrastructure, theoretically consolidating 28% of the U.S. search market and mounting the first credible challenge on Google in a decade. But it's not too early for marketers to wonder if they need to ask: Do we, uh, speak Bing? One thing is certain: figuring that out is going to amount to a mini stimulus package for digital agencies and search-engine-optimi