Android apps, in general, are not as well designed as iOS apps. They're not as well designed as Windows Phone 7 apps either. I would even say they're not as well designed as Symbian apps. I think a big part of this is because of the "google effect"; Google generally doesn't seem to care much about design, details, or even actually finishing anything it releases. 

Maybe the new Android Design site will help; it's a nice start. It seems like a work in progress — for example they list design principles but without any elaboration or examples. You have to start somewhere though, and having design principles at all is a good step.