@Tru Ninja: "3e and 3.5, wizards were overpowered"
Very true. In AD&D 2nd Ed, wizards could become very powerful, but for the first 4-5 levels they were vulnerable and this made playing a wizard a long-term challenge. 3e also made Clerics FAR too powerful. Access to EVERY Clerical spell? Whose stupid idea was that?
"I liked 2e a lot but it was certainly not user friendly for newbies"
If a whole group of new players, none of whom had ever played D&D before, picked up the 2nd Edition core rulebooks and tried to run a campaign from scratch, it could certainly be very hard at first, yes. But as long as the DM is experienced, no system should be daunting for a new player, because only the DM really needs to know the rules. It's not essential for the players to know the rules at all.
@ CrazyAnglican: "I'm thinking that it's just very different. I do like the idea that you can deal damage and knock a character off it's feet or force it to back up."
I've always just done that anyway, depending on the environment and circumstances.
"...so I sold them on it as "World of Warcraft Unplugged"..."
Nice. It's always useful to have something ready for when someone inevitably asks "so what is this "D&D" all about anyway?" I like to begin with a 'thought experiment' that pitches the questioner into actually playing D&D without realising it. Something like: "Ok, imagine you're a fierce Norse warrior on your way back home from a successful voyage. In rough seas, your longship hits a rock and sinks quickly. You manage to swim for shore, and after an exhausting 10 minutes in the cold, tossing sea you gratefully haul yourself onto a shingle beach. You're cold, wet, and gasping for breath. As you try to get your bearings, you hear an ominous howl coming from the woods near one end of the beach. WHAT WOULD YOU DO?"
... and the person generally either suggests a course of action or, if they're one of the clever ones, they ask questions - Can I see anyone else from my ship on the beach? Has anything useful like weapons or provisions been washed up from the wreck? etc etc.
This conversation goes on for 5 mintues or so, then I say: "So, remember you were asking what D&D was? Well, you've been playing it for the last 5 minutes!"
@ Tiresias: "Making a real world around them helps ground them, too."
Tiresias +1. The single most important thing about any campaign is making sure your campaign world/setting has depth, comes to life, and feels 'real' when the players are exploring it and interacting with its inhabitants. I spend hours working on the background to my world - the histories of nations, cities and families, the politics and relationships between states, communities, guilds, and major NPCs, and so on. I've spent hours working out the details of locations and NPCs my players may never meet, but it's worth it because the bits they do stumble across seem rich and vivid in detail, and it's easier for me, as DM, to hold their attention and make them feel involved.