Now this looks an interesting development. The only problem I see is that Apps developers may not be interested in supporting devices without marketing data. OTOH, if the system is much the same as Android, perhaps it doesn't make any difference.

One of the more interesting devices here at Mobile World Congress is Blackphone: a pro-privacy handset being developed by Spanish startup Geeksphone, in partnership with U.S. security company Silent Circle using a “security-oriented” Android build called PrivatOS.Android-Based Pro Privacy "Blackphone" Demonstrated [techcrunch.com]