With Bing taking over Yahoo Search, webmasters are going to need to evaluate their need to address their own sites with regards to optimizing for Bing.

While optimizing for Bing is generally a good idea anyway, those who see a good deal of traffic from Yahoo Search, are going to want to give this some special attention. Presumably, it doesnt matter if you rank well in Yahoo now, if you dont rank well in Bing. At least it wont matter when the change comes. If youre ranked number 1 in Yahoo, but youre on the 7th page in Bing, youve got some work to do.