Are you engaged in any SEO or PPC efforts on any web sites? Do you know your relative rankings (for SEO) or cost-per-click (for PPC) in Bing vs. Yahoo? If not, now's the time to start analyzing those numbers.
It looks like the Microsoft / Yahoo search deal is about to close, and Bing will become the new search engine behind Yahoo. When that happens, all of your Yahoo ranks and costs will change. It will probably be a couple of months before everything is finalized, which gives some time. So, between now and then marketers should develop and execute plans to modify SEO and PPC efforts to ensure consistent Yahoo results.
Domus is currently undergoing this review with its clients. Are you?