We knew this was coming, AOL Search is now powered by Bing. Bing confirmed this saying "as of Jan. 1, Bing powers AOL's web, mobile, and tablet search, providing paid search ads and algorithmic organic search results to AOL's properties worldwide."
You can see it by going to AOL search and looking at the footer. The powered by Bing disclaimer is placed there:
Our partnership with AOL brings additional scale and opportunity to advertisers and marketers. Today, 1 in 5 searches happen on Bing.com, and by providing Bing search results for the number 3 (Yahoo) and 5 (AOL) search providers in the US, Bing powers close to one-third of US PC web searches.1 Today’s announcement is testament to Microsoft’s ongoing focus on search and search advertising and our increasing scale that connects a marketer’s media buys to new publishers and audiences to help them achieve more impact for their business.
AOL doesn't have that much marketshare but this is 100% a big win for Bing over Google.
Forum discussion at WebmasterWorld.