Did any of your hear that Apple and Microsoft have and agreement that MS's mobile products won't look like Apple's? That is one reason why the Windows Phone OS is so radically different from both iOS and Android. Some think it is superior to both, even though its market share is tiny in comparison. True innovation is hard work and doesn't not happen everyday. What most refer to as innovation is not really innovation, it just a simple tweak or rehash of what has been done before. Little is truly new under the sun these days.
I also don't believe in living in one eco system, but I do tend to be loyal to brands that consistently work well for me. If you burn me on a product, I will be leery about other products from you. Google burned me bad with the Google TV...then HTC burned me with the Droid Incredible (Android phone). My Acer Iconia is not a very good tablet (IMO, but it does have some good points), but I don't really blame Acer for that. MS burned me for years and years with Windows, but I think most of us were victims there. So far, Google/Asus are doing well with the Nexus 7, even though apps have started FCing on me. JB remains buttery smooth. I like Asus as a company so that is really why I bought the Nexus.
I've read such, but I don't think there need be agreements that you won't copy one another, lol. Just go and do it. I think innovation isn't that hard; there are plenty of prototypes floating about, for instance, with lots of individuality.
The thing is, companies mimic because they're afraid of risk. That's why you'll see a slew of books or movies of the same ilk at the same time. It's not that no one can think of anything different. It's that people think they'll have a better shot at making a buck. If this billion dollar decision has any possible good, it will show companies that copying carries its own risks.