At the genesis of the planning for this effort, the assumption was that the core deliverable would be some collection of written material on best practices and advice for application developers. The form is TBD (wiki material, a formal document, a bestselling book).
As the charter was drafted, thought was given to expansion to prototypes or demos that might make some of the concepts more concrete than prose alone. The charter also allows for the possibility of material that might be targeted at specific platforms or frameworks, suggestions for APIs to adopt, or other lower-level deliverables. This would obviously require more time from participants and technical exertise from particular domain experts, likely as a result of outreach.