Obviously a lot (understatement) has already been said about the Google’s OpenSocial announcement and the lack of Facebook’s involvement. It pits the two buzz-machines against one at arguably the heights of their power right now – and they would seem to be enemies, but lets not forget that up until a couple weeks ago Google was holding 13th hour negotiations to try and buy a piece of Facebook. Google didn’t want to leave Facebook out of their plans, in fact I’m sure they wanted them right in the center of it. But that is what contingency plans are for. Facebook, of course, went with Microsoft, and now they risk a proxy war against all the other social networks just as Google and Microsoft continue theirs.

I’ve said it before, and I’ll say it again: Google vs. Microsoft is turning into one the greatest rivalries on the planet. It’s Yankees/Red Sox, it’s Michigan/Ohio State, but this isn’t between sports teams with millions of dollars in payroll, it’s not between two school with thousands of alumni, this is between two companies worth hundreds of billions of dollars, the companies that are currently the 3rd (Microsoft) and 5th (Google) largest companies in the United States – and they are absolutely duking it out in multiple arenas right before our eyes. The best part is, this isn’t sports, so there doesn’t have to be any sportsmanship.

You may think this latest Google OpenSocial movement is an attack on Facebook – and it is – but only because Google wasn’t able to secure a stake in the company. In my opinion this has just as much to do with Microsoft as it does with Facebook. Facebook supposedly hasn’t even been approached by Google about the new platform – that’s odd considering every single other major social network has – even MySpace joined on, the network that is still much larger than Facebook. You’d think Google would have at least talked to Facebook about it, but no, they’re pissed off.

Both Erick Schonfeld and Mathew Ingram made astute and interesting observations today when comparing a solo Facebook vs. the new Google mega-team OpenSocial to Apple vs. Microsoft in the 1980s. Apple of course decided to go it alone believing their relatively closed system would work best for them – and nearly died for it, while Microsoft opened up to all and flourished. The strange thing here is that Microsoft is the one backing the “Apple” in this case, Facebook.

Facebook may still join OpenSocial; perhaps Google is just giving them the silent treatment for a bit as payback for the Microsoft deal, but you can bet Microsoft will not want them to and you can also bet Facebook doesn’t really want to with a thus-far winning formula already in place with their platform that is entirely different from Google’s. The only reason I could see them doing it is if public pressure becomes too strong if Google’s network starts to take off. Even then they would almost certainly only throw mild support behind OpenSocial and continue to focus on the Facebook Platform.

Things are going to get even more interesting next week when Facebook unveils their new online advertising service, SocialAds. How does Google make all of its money? Online advertising. This announcement certainly won’t help the two company’s relations any. Anyone who’s heard Microsoft CEO Steve Ballmer talk recently about online advertising (and about social networks being “faddish” for that matter) will know, that is the real reason behind the Microsoft/Facebook deal.

Microsoft can take a breather on their front in the war with Google for a little bit, Facebook is doing a fine job fighting for them.

[UPDATE]: OpenSocial’s APIs are now live – and naturally, they have a blog.