A few comments and questions while digesting the news that Nokia will engulf the remaining portion of Symbian that it doesn't already own:

• How will Microsoft respond? Despite executives’ protests to the contrary, this move by the world's No. 1 handset maker makes the business model for Windows Mobile, in the long term, untenable. Symbian already is the world’s leading operating system for mobile devices, with around 60% of the global market. It will take a couple of years for the Symbian Foundation to release the mobile-phone operating system as an open-source platform, but Microsoft is now clearly standing in the way of a flood tide of openness and innovation from a variety of sources. The contention that integration with Windows on the PC makes the Windows Mobile licensing model ($14 per handset for manufacturers) worth it will be seen as a joke, a few years from now. Earlier this year Nokia was reportedly in talks with Microsoft to start making devices running Windows Mobile. So much for that.

• What does this mean for Ovi? Nokia's effort to shift from being a seller of devices to being a Web services company hasn't gotten much traction, frankly, since its announcement last fall. Nokia just said it will bring the N78, a sleek multimedia smartphone that features Ovi, to the U.S. But as the mobile world moves more toward an open standards, open source model -- i.e., like the fixed Internet -- the value of a service like Ovi starts to sound more and more like the old America Online. Who needs it?

• Is Android over before it gets released? Google recently pushed back the debut of its own open-source mobile OS to late this year -- or perhaps 2009, according to mobile and wireless analyst Jack Gold. The transition of Symbian to a fully open platform removes the whole raison d'etre for Google's project, which was conceived in opposition to RIM's BlackBerry, Windows Mobile, and other closed systems. Google, of course, can afford to be sanguine:

"Openness fosters innovation, benefiting consumers," the search giant said in a short statement responding to Nokia's announcement. "We're very pleased to see other major players in the mobile industry moving in this direction."

That's nice, says Gold, but "Google is finding it's not an easy task building a robust and feature rich mobile OS. ... I suspect many of the members [of the Open Handset Alliance] who joined in this effort are now hedging their bets."

We've seen Google get very good at using its open standards model to invade other companies' territory, like Microsoft's Office franchise. Now we'll see if it's equally good at cutting its losses and retreating.