Some concerns and questions, hopefully factual enough.

Regarding the "other half"

What is called by jolla "a mobile revolution"¹ seems to fit the description of regular auto-run functionality wrt. hot-plugable media. The functionality implies a USB interface connection (or similar) to the back cover. This could also provide extended functionality such as a better camera/flash, buttons or a bigger battery², if the circuitry powering the USB port supports it.

- What kind of interface is used for the "other half" and how deep is the level of interaction with the device developers can expect? For example would we be able to connect our own devices/hardware and load our own drivers for them? Or will we only be able to use ready-made hooks provided by the SDK to access predermined types of functionality like changing color?

- According to ² the interface will be "open to third parties". Does this include the community
at large or only "partners", with no detailed information on protocols freely available otherwise?

Regarding the OS and UI

Judging from the quote above and other PR, Jolla seems to focus on individualizing the look and feel of one's personal phone to one's own liking (being "unlike" via "Ambiance").

- Does jolla's concept of "being unlike" extend beyond choosing a different color theme for the UI and what constitutes inserting a memory card with your music on it, or "is that it"?

Jolla seems strongly highlight their Ambiance feature when talking about their product, implying a strong opinion about how the UI should look and be used.

- Can we modify (manually/with custom apps if need be) other aspects of the UI in ways usually considering theming, or will the look/workings of the UI be locked down to prevent a non-Sailfish look? Examples would be changing icons, indicator placement, changing the layout of kinds of information displayed on the different view panels (feeds view, status menu etc).

¹ Jolla.com
² http://pocketnow.com/2013/05/20/joll...ew-marc-dillon