I always wished BlackBerry would adopt Android operating system. It desperately needs some enterprise hardened secure version with good VPN. Also I really miss decent Android phone with Qwerty keyboard.
Not to mention that Google don't do Android out of the goodness of their hearts. They want to make phone handsets commoditized with all the cool stuff in the software and in their "cloud". That's not a market you want to be in as a manufacturer - just ask IBM who were driven out of PCs, a market they created...
Most of Android components are open sourced. There are versions of Android which strips out Google stuff. For example Facebook released their phone which runs on Android. There is even alternative OS (sailfish) with similar architecture, which runs Android apps just fine.
The problem is that BlackBerry tries to be manufacturer. They do everything by themselves. Instead they should focus on services and existing standards.