The Demonstration site is similar to Google Play & the App Store except perhaps for the well-known restrictions/limitations it places its downloadable “apps” - its cdf files. Remove these and it might simulate richer, more useful and sophisticated "demonstrations" - what I’ll coin “Interactions”.
What would be the biggest hurdles to creating such Interactions?
Complexity: Too many dynamic variables would slow down any viable interaction.
Technical/Security: Integrating permissions, e-commerce platform, notebook/ipad/tablets, Wolfram alpha, would be too difficult.
Design: There would need to be a long lead-time for Tufte-like principles to be developed for these new interactions.
Cultural/Business Model: Too much control is being ceded by WRI.
Human Perception: The busyness of interactions with too many dynamic variables would overwhelm human perception.
None of these strike me as particularly insurmountable hurdles?