Sony actually did this with the PlayMemories stuff - the Alpha cameras run on Linux with an Android subsystem that allows for "apps". However they completely and utterly botched the implementation - no way for third parties to write apps on their own, and their own apps were all pay-only. So they took it out in the latest Alpha 7 series - and with it, unfortunately, also the jailbreak ability which means one cannot unlock the video recording length any more.