Hm. Let's see. I quit playing 3rd edition a good year before 4th edition was even announced, so as you might imagine, I never had an incentive to try it out in the first place.
But I will admit, Essentials is intriguing. I might just buy the Red Box and give it a shot.
Best case scenario, I discover that it's a wonderful miniatures skirmish game, and it sits next to Labyrinth Lord on my shelf of go-to games. That way, I can pull out Labyrinth Lord when I want a game that plays like "Final Fantasy," and Essentials when I want a game that plays like "Fire Emblem."
Worst case scenario, I'll get a nifty red box to store my Moldvay and Mentzer booklets in.