It seems that Yahoo! (NASDAQ:YHOO) and Microsoft (NASDAQ:MSFT) are speaking the same language. Last night, the two Internet juggernauts announced voice-chat interoperability between Yahoo! Messenger with Voice and Mr. Softy's Windows Live Messenger.

It's a pretty bold move, even if it's not entirely unexpected. The two bellwethers announced that users of one service would be able to text-chat with users of the other back in October. The new agreement adds voice-chat capabilities to that arrangement, creating a powerful community 350 million accounts strong, according to internal usage statistics. The companies announced that beta testing had begun last night, with widespread availability to follow in the coming months.

Redrawing the battle lines
Microsoft and Yahoo! may seem like unlikely partners. They are fierce rivals in paid search, where they continue to trail Google (NASDAQ:GOOG). In instant messaging and voice chat, eBay's (NASDAQ:EBAY) Skype is the latest buzzworthy global brand, while Time Warner's (NYSE:TWX) market-chomping AOL Instant Messenger is one of the few remnants of the America Online empire that still matters.

You could argue that Yahoo! and Microsoft's partnership is throwing the gauntlet at eBay's feet, but is it really? Yahoo! and eBay recently hooked up for a strategic advertising alliance, so one would think that the two giants are on relatively friendly terms. But AOL has been a billboard for Google's contextual advertising for years, and Google recently invested $1 billion to acquire a 5% stake in AOL.

Like so many things in the Yahoo! and Microsoft playbooks lately, it's all about Google. Don't believe me? Check out the WWGD bumper sticker on the back of Steve Ballmer's car! Joining forces to make AIM a little less dominant would hurt Google by winning back some of that billable real estate. More importantly, though, the deal seems designed to crush Google Talk before it has much of a chance to fly.

All you do to me is talk Talk
It's been nearly a year since Google launched Google Talk. Like so many of Google's non-search gizmos, it's been tagged as "beta" for an eternity. The rub here is that Google Talk hasn't really wowed the public in its infancy.

That's unusual. Google is used to being either a category killer or a silent killer. Look at the perfect simplicity of its landing page, or its AdWords and AdSense advertising programs. Look at the jaw-dropping beauty of Google Earth or Google Maps.

Google Talk? Eh. It's not exactly shabby, but it's not Google's finest hour. That's OK, though; Google doesn't have to hit them all out of the park. Perhaps Google Talk is like those alien baddies in the War of the Worlds remake, buried in the ground and lying dormant until the time comes to arise from its slumber and strike. Integrating the program with Google Checkout transactions, or tying it to AdWords' recent move toward "click-to-call" functionality, might be the elixir to make Google Talk a real monster.

Microsoft and Yahoo! can't afford to see that scenario play out. Google Talk must perish, and the bloodier, the better. As the world's leading software company, Microsoft has more at stake than paid search. Yahoo! also has diversified interests as a leader in online dating and job hunts. Yet both still fear Google, with good reason. Google has been nibbling away at Microsoft's desktop space and Yahoo!'s Web-surfing audience alike. Judging from Google's heady growth trajectory, it will rule the planet by 2034 -- a few years earlier than that, if it's able to secure the book and movie rights.

It's great that Microsoft and Yahoo! now offer interoperability between their voice-chat platforms. It will make it that much easier for them to get together and mutter the three words that they've no doubt been volleying back and forth lately: Google must die.

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Longtime Fool contributor Rick Munarriz is an equal-opportunity user of all of the portal's nifty services, but he does not own shares in any of the companies mentioned in this story. The Fool has a disclosure policy. Rick is also part of the Rule Breakers newsletter research team, seeking out tomorrow's ultimate growth stocks a day early.