First of all, thank you Mr. Mearls for answering questions. Some of the things you have said have done a lot to allay some of my concerns.
I think I've seen enough of the Essentials classes to definitively ban them from my table. I'm not a fan. The elegance of the 4E system is what sold me so completely on it, and I have no interest in going back to an older, simpler style, or dealing with the balance issues arising from mixing Essentials with Original 4E. Overall, I think 4E is the best balanced system I've ever run. Maybe Essentials is for some people, but it's not for me.
I think that my main problem with the system is the marketing behind it. If Essentials were marketed as D&D Starter or D&D Basic, I would have no problem, because it would be understood as a system for people just getting into the game that's a little bit simpler and easier to use. As it is, the intent seems to be to produce regular products with support for both systems, but I have no desire to pay full price for a book that's half-filled with another system I won't use. This is a problem to me. The analogies put forth about a restaurant menu are fairly apt, but they actually argue against the viewpoint of most people using it. There's a good reason why the finest restaurants have very small menus, or even no menu at all (This is what's for dinner. You'll love it.). It's because splitting focus among too many dishes means not as much attention to detail is spent on each type of entree. The chefs aren't as good at each entree, and the production isn't as easy to quality control. Sure, you can expand the kitchen and employ more chefs, but with increased size comes complexity in the organization, and suddenly you're either introducing more problems into the process due to the difficulty of training and managing so many people, or you're serving a poorer product. Try eating at a restaurant with a very short menu. You'll thank me for it. I worry that supporting two different menus of classes will reduce the overall quality of product coming from WotC. I know they intend to try to keep everything balanced and not to let either line suffer. I just don't think they (or any other RPG company) can do it.
As to the "4E is too hard for some people" theory... honestly, the easier systems are great for people just getting into the game, especially if it's some kids in junior high that have never had exposure to a real gaming group before. But if I had someone in my group that couldn't grasp 4E after repeated sessions, I'd think about not gaming with them. The system isn't hard. If they can't figure out that 2d8 is more than 1d8, they probably won't be able to understand the story that we're trying to tell anyway.
And finally, I don't think that what we've seen of the Essentials classes achieves their goals of simplicity. Most of the complexity of the 4E fighter is still there in the knight... it's just disguised with a new coat of paint. Now with the stances we're pretending that they make melee basic attacks only. Great.
Ultimately, Wizards correctly observed in the past that having multiple editions of the game out simultaneously split the fan base and was not as profitable. They also realized the problem of introducing radical changes to an edition before the fanbase feels that the edition has had its natural life cycle. With Essentials, they're trying to have their cake and eat it too. Just saying it's not "4.5" doesn't make it so, when the changes are arguably more intense than the 3.5 ones were from 3.0. Just saying that it won't split the fanbase doesn't make it so when there are two different sets of classes that do the same thing in radically different ways, and when support is going to be split between them.
With no malice intended towards the designers, I hope that Essentials dies a quiet death, and we can all move on with the cool things still waiting to be released for 4E.
Why is Essentials so interesting around here? Here's why, for over two years, a lot of us assumed that 4e was going to be on the numbered supplement book for a good long while. I was sure that there was going to be a an Arcane Power 2, and Divine Power 2, a Primal Power 2, to go along with Martial Power 2 this year. Until I learned otherwise, I thought that DMG 3 was going to make my September. That perception has changed, however, by the fact that Heroes of the Fall Lands isn't just a reprint book with maybe some new powers. Actually, it started with the announcement that this year's campaign setting is Dark Sun. The the product schedule was filled with Gamma World and Beginner's books.
Now those beginner's books have some great ideas in them. For years, Wizards has been putting out beginner's sets with pre-generated PCs a short adventure, and some rules with short "buy the PHB, DMG, and MM to continue the fun!" and now, that's not the case. And it's very interesting.
That's a perfect encapsulation of why I'm so disappointed. I see a year full of products that I have no interest in because D&D is veering off an a weird beginner/oldschool/CCG boardgame tangent. I liked 4E so much specifically because it rejected that stuff. And a CCG boardgame is an abomination of Lovecraftian proportions.