Wow. Well, I must say, all of my worries and misconceptions are gone. The Essentials line is an addition to fourth edition D&D just as if a new Players Handbook or Monster Manual was released. It is not to replace anything! This is great news! I'm willing to embrace expansions on the current system (especially at the lower price point) easier than if Essentials really was a different version of 4E. Thank you Mike and Paul for filming this and putting me at ease.
Personally, I'm not interested in the tokens (I have over 350 miniatures) but I can see how new players would not have the same kind of existing resources I have collected over time.