There will be significant changes in who is permitted to write a program for Windows 10, and tight controls on a special Microsoft-Only signing process required to use a program. Corporate IT will be provided access to a special version of this signing process so that they may create their own internal apps.
I recommend that anyone interested in the impact of deploying Windows 10 log in to http://www.microsoftvirtualacademy.com/ and take the short half hour courses on “Windows 10 Technical Preview Fundamentals for IT Pros”.