Bing may already be powering Yahoo search, but it is still behind in terms of where people are actually searching from. That may soon change, however (at least in the U.S.).

comScore has released its monthly U.S. Search Engine Rankings report, and it shows Microsoft sites gaining on Yahoo sites. In terms of explicit core searches, Microsoft is right on Yahoo’s tail.

In terms of total core search queries, it’s not quite as close, but again, the gap is narrowing.

It goes without saying that Google is still the frontrunner in both categories by a pretty wide margin.