Since neither Yahoo! Inc. (NASDAQ: YHOO) or Microsoft Corp. (NASDAQ: MSFT) seems to be hurting Google Inc.’s (NASDAQ: GOOG) online advertising business, reports have bubbling up (again) that the companies would merge. While that may not happen, a partnership between the two companies is probably underway (and under wraps) as these two juggernauts scheme to soak in some of the revenue Google is single-handedly enjoying right now.

On that note, Yahoo! CEO, Terry Semel, will be present during the Microsoft Strategic Account Summit meeting that happens every year. Generally, Microsoft and Yahoo! are mortal enemies when it comes to competing for online ad dollars. However, the two are becoming more cozy with each other from all those late-night strategy meetings where both are contemplating how to best attack Google.

Yahoo!’s Semel was booked for the Microsoft Summit long before word got out last week that Microsoft’s acquisition talks with Yahoo! again fluttered away. What Semel will talk about in the face of a current and large rival is a multi-pronged partnership (something Yahoo! loves to do these days) aimed at raking in some ad dollars from Google’s grasp.

Both companies need to be able to turn search queries into cash, but both aren’t nearly adept at it as Google is — nor do both companies have the market share Google has. Can a partnership turn that around? The partnership will have to surpass Google’s search numbers (no easy task) and then monetize it as effectively as Google does. Are you betting on that scenario? I’m not sure I am — yet.