Remember when everyone feared MS? I mean, that was really terriying time for our industry. How forgetful is it to "wish" MS could gain a third of the phone OS market shared... Apple and Google conjugated efforts kept the wolf outside and you want to open the gates?
However, I agree that a domineering Android/Google or Android/Samsumg is harmful for the market. Let us hope some other OSes can grab a piece of it. I have some hope in Cyanogenmod, which could be forking away from Android (just like Linux forked Unix). And, if you look at it, that is just what Chinese companies are doing (xiaomi, etc.): forking Android and gain market shares.