There is nothing ironic about it. DL, or any other carrier intend on using iPads as EFBs, will have to go through an approval process which will address all safety issues.
Class 1 and 2 EFBs, which an iPad will fall under, are subject to the same restrictions as PEDs and will be used accordingly. They will also be what is known as controlled devices, meaning each individual device's software and hardware standards will be under company control.
The only way a passenger can comply with the regulations is to switch off and stow their PED.
This was all discussed at length recently. If you are interested the thread should be easy to find.