Think about it. I'm looking to buy a Rules Cyclopedia, and cruising EBay, and it hit me. If I want to buy 1st edition books now, the list of books needed is known and straight-forward. Same with 2e and 3.x 2e has the players options thingy to deal witth, which isnt a big deal, and 3.0 and 3.5 are 97% the same.
When we're in the 6th edition days, when D&D is a boardgame with magic-type cards, and some 4e grognard tells his friends to buy 4e books off of ebay to play in his game, WTF does he tell them to buy? The PHB is essentially useless as a book, due to like 500 pages of errata. DDI is offline or updated to 6e, since they only support the latest edition, as we all know. And I still don't know where this whole Essentials line of products fits in to the scheme of thing. The Rules Compendium? The other books suggested by WOTC to buy? WOTC's lack of willingness to number their latest editions by edition? Their refusal to admit that there is a new edition at all with Essentials---or at least a half edition? What the hell does a prospective player buy 4 years from now when WOTC is on 6e?
BTW, I don't thing WOTC has begun work on 5e yet---because they have not publicly denied it over and over again.