EncycloWikiSemantiPedia?

What form(s) will the 21st century encyclopedia take?
Compared with its traditional progenitor—the printed, bound, multi-volume mini-library often shown off and delivered by a door-to-door salesperson—what will it have in common, and what limitations will it overcome?
Will it:
- Know who, where, and when you are
- Allow you to be a contributor
- Be with you anywhere and everywhere
- Grow exponentially every year, week, or day
- Maintain its authority
- Be initiated by a small group of people
- Be “completed” by a large group of people
- Have a clearly defined scope
- Have a good match between its reach and its grasp
- Have boundaries
- Have a single interface
- Consist of a big, open dump of data into the circulatory system of the networked environment and be expected to fend for itself
- Cost you money
- Be necessary
Feel free to contribute your answers or further questions in Comments.

Has Wikipedia closed the book on this subject? What if your goals are not to be the one and only comprehensive resource, but rather an encyclopedia about a defined field, subject, or place? Like a US State, for example.
Via Twitter — @pomeranian99: Length of Britannica’s entry about Wikipedia: 913 words. Length of Wikipedia’s entry about Britannica: 6,804.
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