Still immature and architecture does not seem fully thought out
I was also at that Android "hackathon". The questions I asked had no real answer.
The framework looks interesting because it lets applications smoothly share functionality. One application can take the user into another without the user being aware of the switch between applications. As far as they are concerned, they are just moving between steps in a single workflow.
However, that has implications for API, standardisation, security and testing that do not yet seem fully developed.
The capabilities of one application become an API for other applications on the device. Google seem to be relying on the market to standardise on those APIs, even for functionality that the user would expect to be core to the device (todo list, calendar, media player, etc.). The alliance members are contractually obliged not to fork the platform APIs and deploy incompatible platforms, but services provided by applications are a grey area.
The ability of applications to share functionality also affects testing. An application can expose instrumentation interfaces that let it be controlled when deployed on the device for functional testing. But if an application can seamlessly switch to functionality in other applications and back, instrumentation interfaces that correspond to intents must also be published and standardised, or it is impossible to test the application.