Ever since Facebook announced its new "Home" launcher for Android the conversation surrounding the "forking" of Android has been increasing in volume. The idea seems to be that because Android is open source, any company or OEM can/will take Android and heavily customize it into something unrecognizable. This company will then replace Google's services with their own and then aahhhh its the end of the Android world because... well that part starts to get a little muddled. First, we need to try to look at this from Google's perspective. Why did Google create Android in the first place? Because Google wanted to ensure that as more and more people were turning to their mobile devices instead of their desktops for information Google services would continue drive traffic to advertisers. That is it. That is why Android exists. Why is Android open source? Android is open source because Google wanted every device manufacturer to be able to customize Android and make it work for their customers and on their devices. The point I'm trying to make is that a "skin" or launcher like Facebook Home is taking advantage of exactly what Android was designed to do.
The only company to successfully fork Android so far has been Amazon. Yes, Amazon has replaced the Play Store with their own app store. But very very few companies are capable of that level of development. Also, we shouldn't forget that Amazon's version of Android that runs on the Kindle tablets is still based on Ice Cream Sandwich. And the spectacular features that have been added to Android since 4.0 are missing from the Kindle line of tablets. But the most important thing to remember is that, as Apple recently discovered, replacing Google services with your own internally developed service is very very difficult. Even a company with the resources of Facebook didn't even want to take on the task, and Apple, the most profitable company on the planet, couldn't successfully replace even one Google service (Maps).
We all need to calm down, and take a step back before we predict the collapse of Android into a multi-forked mess. Nexus devices are increasingly popular. Google services are getting farther and farther ahead of their competition every day. And all of this is unlikely to change anytime soon. Android's open source nature is not its biggest weakness, it is its biggest strength.