It seems Microsoft bing got sued by Bing LLC a small design company based in St Louis, Mo, USA.
Bing! alleges trademark infringement as well as unfair competition, claiming "Microsoft's use of the name dilutes the value of it and confuses the public about the companies' relationship to each other." The design company has used the name since 2000 and has pending application for registration of the mark.
I hope Bing LLC wins the dispute :p