> You can create separate app store (like Amazon and Nook are doing), but this will require significant marketing to attract the developers to your store. I don't see anyone with deep enough pockets interested.
There are alternative app stores for Android. Have been since the beginning. And not just Amazon. There were others before that.
The problem you are alluding to, of course, is that while Android is open source the Android apps are not. So Google has certification requirements for the platform before you can distribute their software at no-cost.
This is not a insurmountable barrier. I don't know what would be required for Ubuntu to make a 'frankenstein' OS, but it's something they will have to work with Google to do if they want people to have access to the Google applications they are familiar with.