Oh, thanks for the correction. I had assumed that JetBrain develops Android Studio and Google just puts their stamp on it.

Well that pretty much is what happens. JetBrains wrote IDEA and the Android support for it. Google made some small modifications (some good, some detrimental), and packaged it with the Android SDK.

The biggest change was to switch to gradle which is a more powerful build system but also much buggier (at least in the current Android Studio). They also lots of useful Android-related tools and lints, and a fair helping of UI bugs.

Still, beats Eclipse by a country mile.

Only when it offers better support than CDT for the NDK and all those Grandle bugs get properly fixed.

Could you elaborate on the detrimental modifications?

It's Google the one that added all of those nifty Android-specific features, like seeing how your app looks on multiple resolutions/screen sizes at once.