So, while correcting one of the most embarrassing problems a software company has ever had, Apple basically ‘broke’ the enterprise deployment model. Oh well, we can all understand why they’d choose to do this 
Anyway, if you’ve had your own deployments for install via http…they will not work with clients upgraded to iOS7.1. The request for the plist is required to be https now. Simple enough, get a cert and configure url with https…done!
Some info on stackoverflow