As mellis said http://news.ycombinator.com/item?id=2369108 they shipped product so the source should be good enough to ship also.
* They made sure that many of the most compelling -- to end users -- built-in bits were proprietary (i.e., those sweet Google-branded apps that you can get C&D'd for distributing)
* They began imposing requirements above and beyond software license compliance if you wanted full access
* They made sure their default (and thus, to most users, only) marketplace had the same sort of remote kill switch people complained about in Apple's ecosystem
* etc., etc.
Android is a mobile platform that you can sometimes get source for, sometimes hack on, and sometimes do what you like with. Which, um, isn't any idea of "openness" I'm familiar with.