WOOO HOOO!!!!
OK so I finally got it...
this is what worked for me with only deploying one (1) Headless app.
Step1: Open Powershell as Administrator
Step2: Connect to the board with this command: net start WinRM
... NOTE I had an Ethernet cable directly from my laptop to the raspberry pi 2 board. NOTE if you've been running VS already, it'll tell you that you've already establish connection...
Step3: in powershell, run this next Set-Item WSMan:\localhost\Client\TrustedHosts -Value minwinpc
... I've left the default name for my device. NOTE when prompted, type 'Y'
Step4: Enter-PSSession -ComputerName minwinpc -Credential minwinpc\Administrator
... NOTE You will be prompted for password... assuming default, enter "p@ssw0rd" - yes, case-sensitive
Step5: wait a little while... seriously it takes a moment...
Step6: in powershell, you will now see the device name in the prompt - type the following command: IotStartup remove
Step7: in powershell... type : IotStartup list
... from this we want to get the name of the headless app you want to default to.
Step8: in powershell... type: IotStartup add headless <the-exact-full-name-of-the-headless-app-here>
step9: in powershell... type: setbootoption headless
.... this will prompt you to reboot if successful
step10: in powershell... type: shutdown /r /t 0
... this will cause your device to reboot, immediately
--DONE.... from here just wait for you app to kick off! I had a simple LED program and it started eventually on it's own after the reboot.