How about the Google apps?
On the one hand, everyone complains about fragmentation with multiple devices and multiple resolutions and not every phone getting Android updates; on the other Wired says device makers who do Android things that aren't phones aren't getting the OS love - they want the marketplace and updates and device certification and a framework for making sure apps can be compatible.
Actually, it's all the same issue; how does Google support Android across the range of devices users want, even if those devices may not fully support Google's ad business model and may not make Google as much money as searchtastic smartphones. (Google may also be too busy, thinking Chromium is a better fit or having some other reason for not having a clearer developer strategy for the non-phone space).
I'd like to say the advantage of a paid-for licensed smartphone OS is that you get lots of different form factors supported, but given how badly that's turned out for Microsoft with Windows Mobile I'll say that having an OS is more complicated than just writing and handing out the code and the industry is still working through what level of closed, controlled or open and permissive systems work the best.
This doesn't just affect small, no-name manufacturers; when Intel first put Android on a netbook Google's reaction wasn't 'that's cool'; it was 'take the Google apps off there, they're not open source'. T-Mobile showed us a 15" Android tablet at CES this year that's primarily a home calendar system but that they also want to put key apps on.
That's the other question of course: how many apps do you want on something that's not a phone. Do you want a Web pad/tablet to have smartphone-style apps? (iPad advanced orders seem to say yes.) How about an ebook reader; should that have maps on, or games? A picture frame? Well, the Sony Dash Internet viewer comes with a pile of apps on top of its alarm clock-cum-picture frame basics. We've got the app bug and while you don't need a marketplace to put apps on a platform (Windows doesn't have one), it certainly makes it easier on a device with a limited interface.
Android is a really interesting balance of open source and proprietary apps, free-for all development and central certification and control. We don't yet have really good models for how to do that, but there are some lessons Google could learn from Microsoft about dealing with developers and OEMs (as well as a couple - like the HP/Intel/Vista debacle - we hope they don't repeat.