It makes sense. It's a free and open source operating system for mobile devices. It's based on the Linux kernel which many developers are aware of and have experience with. It's backed by Google. Customers want it. Handset makers want to compete with the iPhone. There's a decent number of applications already built for it. There's room for customization so that each manufacturer can differentiate their Android from the other Android units. Why spend your own money developing something that's likely to be inferior?
1) It forces Apple to compete for developer mindshare, improving our lot.
2) It provides an open platform that we can begin to support (and possibly migrate most of our mobile development to).
The OS and APIs aren't as nice, but being able to use most JVM-compatible languages is a big win. I've been holding my breath for a while, hoping that Android would gain traction and we could alleviate some of our reliance on Apple's draconian platform. It sounds like this is now happening.
Not so incredible: The article is about what phone makers and carriers are choosing to ship. For the iPhone, those choices have already been made and are unlikely to change in the near term.