I think one of main reasons why the “mainstream” users don't know much about the “Android” brand, or can't recognize an Android phone that easily is because Google has never really had a marketing campaign for Android itself. This coupled with the fact that each manufacturer makes their “Android” phones look quite different from other manufacturer's Android phones, is why the Android brand is so weak in the market compared to the “iPhone” brand, or “iPad” brand.
Of course, it's also easier to remember an actual product's name than an operating system's name, if you don't care much about this sort of thing. However, if Google would've promoted Android heavily with traditional advertising, the same way they did with Chrome since the beginning, maybe “Android”, as a brand name would be a lot more recognizable. This would be much like the “Windows” brand in the world of PC's; everyone and their mom knows “they need Windows” for their PC's.
Plus, it would get people used to a certain type of UI that stock Android has, and that would lead to 2 things: it would make it harder for manufacturers to promote their own skinned Android devices as Android, and in the same time those who would use stock Android would benefit from Google's own marketing for Android. So it would create an incentive for manufacturers to use stock Android, and a disincentive for them to use anything else, if they still want to call it “Android”. Win-win for Google and for consumers.
But Google didn't do this early on, and it's going to be tough to try this now. Now that they have both a good looking OS, starting with the ICS/Jelly Bean versions, and a worthy physical product, like the Nexus 7 tablet, I think Google will be trying to make more people recognize what pure Android really is about. Then the plan will be to have all these people expect that UI and those features (Google Now, Google Voice Search, etc) in future devices. Of course, this is all speculation on my part.
Google's first step in mass-marketing, is a commercial that is much like their previous ads for other products, that try to show how technology is strengthening the relationship between people. This commercial is showing how the Nexus 7 is making the outdoor experiences between a father and his son, more fun. The name of the commercial “Nexus 7: Camping” also implies that this is but the first of a series of commercials for the Nexus 7.
It doesn't matter how many reviewers think the Nexus 7 is a Kindle Fire killer, if regular people don't hear about it at least.