I train staff in the use of ArcMap and various plug-ins to an organisation which has since diversified its usage of GIS into roles and departments beyond the initial brief of the software. While I have developed custom training courses, tools, and applications to help in the bespoke nature of those job roles, offering the whole 'buffet' to people who only want something from the 'salad bar' can be both inappropriate from a concurrent license point of view and intimidating for the user with more limited and/or specific requirements.
The facility to build a dedicated and scalable subordinate instance of ArcMap for defined job roles would be hugely beneficial. I know at the developmental level this can be done, but our software developers are unlikely to have staff resources to devote much time to this.
A simple user wizard which enabled you to rapidly drag tools and objects onto toolbars, visually style-up and name aspects of the custom interface, then hit a button to package all the hierarchical objects needed for the deployment into a bespoke end product would broaden the organisational scope considerably.
It would also be useful if a certain number of 'lite' licenses could be purchased at reduced cost to allow for these deployments, without conflicting with the higher-end business users' ArcMap availability.