Google sent shockwaves through the tech community today when it announced that Andy Rubin was out as Android chief. Chrome's Sundar Pichai will oversee the mobile platform in his stead. Here's what CEO Larry Page said about the move:

Having exceeded even the crazy ambitious goals we dreamed of for Android — and with a really strong leadership team in place — Andy’s decided it’s time to hand over the reins and start a new chapter at Google. [The Official Google Blog]

The Android co-founder, who first approached Google about a new operating system in 2004, many years before smartphones were the industry standard, was scheduled to speak at the SXSW conference on Sunday, but was suddenly dropped from the bill. Now we know why.

More than a few tech bloggers were surprised, especially considering Android's recent run of success:

Others were already speculating what's next:

MarketingLand's Danny Sullivan has a different theory: Google simply wants to streamline its competing operating systems. 

That leads to a potential similar conflict with Rubin and Pichai. Both have headed up what seem to be rival operating systems: Rubin on Android, Pichai on Chrome OS. Many have questioned why Google needs two operating systems, with Chrome OS often being suggested as the loser. […]

The launch of the Chromebook Pixel gave, in my view, new life into the Chromebook project. Suddenly, it had a Google-branded machine to help push that operating system similar to how the Nexus line has helped Google push Android.

It perhaps was also a harbinger that Google has decided it makes sense to have both operating systems under one head — Pichai — who's been with Google longer than Rubin. [MarketingLand]

Read the rest of Page's letter here.