The main takeaway from Xiaomi's success is that being a ripoff is a valid business model. Not only valid, it can be better than trying to fake creativity. Xiaomi badly wants/wanted to be Apple. What they did with Android might look creative to you, but only if you look at it as an Android. Again, they want to be Apple. They want to have an iOS, modifying Android is the fastest way to get there.
To all the people saying Xiaomi is just taking inspiration - watch that:
http://v.youku.com/v_show/id_XODc0OTA0NzY4.html
I think we just have hard time stomaching the fact that people who blatantly plagiarize can win. We view it as evil and whenever someone does it and wins we try to explain how they really didn't.
It's okay, it's just globalization.