Will Bing grow at Google's expense (or Yahoo's) in 2012?

Will Microsoft's Bing grow search share at Yahoo's expense -- or Google's -- in 2012?

comScore's U.S. search share data for November has Microsoft's Bing and Yahoo search at about 15 percent each.

Here are the latest stats, courtesy of SearchEngineLand. (comScore hasn't made this data publicly available as of December 16.):

For November, Bing was at 15 percent share. Yahoo was at 15.1 percent. And Google continued its reign at 65.4 percent -- down slightly from its October share of 65.6 percent. Back in January 2011, according to comScore, Bing was around 13 percent; Yahoo at 16; and Google at 65.)

(These numbers are measures of "explicit" search share, which removes certain categories of searches that comScore doesn’t deem to be actual “user-engaged” searches.)

One of Microsoft's goals in teaming with Yahoo and having Bing power Yahoo search was to grow Bing's share. The idea was to do this at Google's expense. Back in early 2010 when the pair received antitrust clearance for their partnership, Yahoo had 17 percent U.S. search share, compared to Microsoft's 11 percent (with Google just over 65 percent).

The big question in 2012 will be whether "MicroHoo" grows and Google shrinks -- or whether Bing gains primarily at Yahoo's expense.