Fixing phones properly requires hardware makers to create their own updates incorporating Google’s fix; they test those updates and pass them on to carriers, who also test the fixes before pushing them out to customers. Apps for Android devices, including ones developed by Google, could be updated through the Android Market, but system software has to be updated through the carrier’s channel.
Android is a great model for adoption, but less so as these complex software artifacts become broadly spread, and poorly maintained. For the handset manufacturers, this is a not a completely bad thing — they’d likely prefer that you throw it away and get a new one.
It is close to the time when (for many of us) it will be easier to simply discard the current phone, and purchase a new one without the limitation. Today this is relatively expensive — tomorrow much less so. A cheap, disposable access point. Interesting times.