mhacdebhandia
Explorer
I am pretty much in exactly the same boat, except that I never bothered with the ENWorld pre-release stuff, and I still have all of my Third Edition books (though I don't plan to run or play that game again).Got excited by the previews.
Enjoyed the demos.
Enjoyed running the ENworld pre-release version
Tossing my 3e stuff on eBay was wonderful.
Enjoy running the actual 4e game.
BUT...I have a shelf full of RPGs and I don't need any one game to fulfill all my hopes and dreams 24/7 which seems to be a problem for many people.
Still, D&D Fourth Edition isn't the only game in Mhacdebhandia Town. From where I sit I can see books for Star Wars Saga Edition, World of Darkness, Vampire: The Requiem, Werewolf: The Forsaken, Mage: The Awakening, Promethean: The Created, Changeling: The Lost, and Hunter: The Vigil . . . elsewhere I have books or PDFs for GURPS Fourth Edition, Unknown Armies, NEMESIS, Don't Rest Your Head, Dogs In The Vineyard, All Flesh Must Be Eaten, Traveller . . .
While it's well known that a majority of gamers play some version of D&D, I wouldn't be surprised if the majority of gamers who visit sites like this one play games other than D&D - at least "in addition to" if not often "instead of".