I think there is an ongoing pattern in Google - they are just keep fitting in to all existing niches, taking only the best elements from each competitor or firm in the niche and adding to the mixture their secret sauce, which will finally make their product the best. Notice that they're conquering (and not slowly..) every niche in the market and I'm sure we haven't seen the latest... Pure Google-Made OS is the destination, and it will be substantially better although it was built upon OSX/Microsoft/Linux elements.. That's how you gain popularity.. upon popular "ancestors".