Mercurius
Legend
Merric got to it before I could (and much better and more thorough than I would have had the patience for
).
Essentials is a product line within 4E. It is, in a sense, both a pseudo-evergreen product line and a variant take on 4E, especially classes. The distinction between "classic" 4E and Essentials is artificial in that they are both the same game. WotC could conceivably come out with another variant line next year, with different design precepts. In some ways you could say that with Essentials WotC flexed the muscles of the 4E game engine, displaying how flexible it is.
My guess is that WotC is going to try out some new ideas over the next couple years, gather info, and build towards a release of 5E in 2013 or 2014. How products like Essentials do, and what the response is to variant takes, will impact their design considerations.

Essentials is a product line within 4E. It is, in a sense, both a pseudo-evergreen product line and a variant take on 4E, especially classes. The distinction between "classic" 4E and Essentials is artificial in that they are both the same game. WotC could conceivably come out with another variant line next year, with different design precepts. In some ways you could say that with Essentials WotC flexed the muscles of the 4E game engine, displaying how flexible it is.
My guess is that WotC is going to try out some new ideas over the next couple years, gather info, and build towards a release of 5E in 2013 or 2014. How products like Essentials do, and what the response is to variant takes, will impact their design considerations.