Reports of Yahoo-AOL-Google tie-ups and Microsoft-News Corp. bids are signs we're in for more trench warfare in the struggle for Yahoo's future. And more hints that Yahoo doesn't want any part of Microsoft.Yesterday, Yahoo said it would begin a test to deliver Google ads along with Yahoo results and reports suggested that AOL was in talks with Yahoo and Microsoft with News Corp. about joining up in separate quests for the struggling online company. It's Yahoo's latest -- and maybe last -- stand against Microsoft's $40-plus billion acquisition bid.

Starting off a flurry of a press release and leaks to the Wall Street Journal and New York Times yesterday, Yahoo fired off the first salvo by announcing that it would begin a test to deliver Google ads alongside Yahoo search results. Earlier reports had suggested the possibility of a tie-up, so Microsoft was ready with its own scathing response, including a statement from its general counsel and links to pooh-poohing from analysts and legal experts who suggested a Google-Yahoo deal wouldn't gain regulatory approval.

Meanwhile, the typical "people familiar with the matter" were leaking to the Wall Street Journal reports that Google was only part of Yahoo's new approach to either finding a new suitor or forcing Microsoft's hand. Yahoo is in the market for AOL, the familiar people said. Again, Microsoft was ready, noting that there was no word whether any Yahoo-AOL deal would go to stakeholders, as Microsoft is prepared to take its bid.

As for the other "people familiar with the matter" leak, that Microsoft was in talks with News Corp. to somehow jointly acquire Yahoo? Microsoft isn't touching that "rumor," according to a Microsoft spokesman.

It's a soap opera drama that just won't stop -- the latest plot twist comes only days after reluctant pen pals Microsoft CEO Steve Ballmer and Yahoo chairman Roy Bostock traded angry letters, Microsoft accusing Yahoo of stalling and opening the door to a messy proxy war and Yahoo responding with a sort of "neh-neh-neh, you can't catch us" attitude.

But while Yahoo's move to combine forces with AOL and Google is clearly aggressive, it might never happen. Microsoft is right about the high regulatory hurdle that would come from Google's newfound 90% market share for online search and advertising. And while Microsoft could have potentially walked away if Yahoo continued stalling, it won't go down without a fight if AOL and Google are in the hunt.