Neo900 [1] develops a device like that - privacy oriented open platform, with maximum user control over the device. Even though its specs and price might be a bit unsatisfying to some, it's actually a pretty reasonable approach worth supporting - basing its design on N900 and GTA04 is for a small project like that like reaching the low-hanging fruit, while ideas and solutions developed for it such as baseband "sandbox" or hackerbus will be able to be used later in future devices. See also [2] for more details.
Full disclosure: I found this project so worth supporting, I actually became team member somewhere at its beginning :)
Full disclosure: I found this project so worth supporting, I actually became team member somewhere at its beginning :)
[1] http://neo900.org/
[2] http://neo900.org/stuff/ohsw2014/ohsw2014.pdf