Choice of Technology...
Before making such a serious investment in to anything, the first thing to check is the end of life for support, or what we can call support horizon. As for any smart phone, after about 3 to 4 years it will be too obsolete to be efficiently used. The OS and security would be through many updates, and becoming more demanding on the phone's hardware capability. It would not be a good idea to operate without security and bug updates.
As for custom written software that is OS version sensitive, there should be an agreement with the authors to make sure the software can be easily upgraded, or can be designed to not be version sensitive if possible. It is also apparent, nobody can know specific necessities of an OS that is not yet published or officially distributed.
Personally, for a Smart Phone of any type I would be going with Android. The reasons are simple. Very versatile, not a closed system as like most of the others, and is not a locked in system. If you require ultimate security with Android. the Blackberry is the most secure phone on the planet. Regular Android using a decent Android phone, if properly set up is very secure.
Biting the hand that feeds IT
