I think depending on the situation, these are 4 good guildlines, but the BYOD situation is very complex and will require many different type of solutions to account for all the different business situations. An example: At our doctor owned hospital, the doctors wanted to use thier tablet and smartphones, but didn't want IT to control thier devices. Eventually IT get the doctors a HIPAA compliant text messaging service with HIPAA video and Dropbox intigration (app is Tigertext), which solved the problem and let the doctors feel like IT didn't control the device but security requiremetns were met. It is these kind of innovative solutions that IT departments will need to apply to thier business model.