First off, thanks to CleverNickName for the straight-forward review of his first playtest.
I have run three 4E "Demos" so far. In my case, "Demo" means a single encounter to show off the combat mechanics of the new edition. Right up front i let every player know that the whole purpose of the thing was to explore how a 4E combat runs. I didn't try to create an adventure at all, i simply told them that they had been hired to follow a simple map to the lair of some nasty creatures and destroy the threat to a nearby town.
I've run the Demo for 10 different people. There have been several comments about parallels to WoW (i cannot be specific on these, as i have never played WoW). I have yet to have a player leave in disgust. The players that gave feedback were all positive. The player that had the biggest reservations about 4E has turned out to be the most excited after playing the Demo (He's IM'd me each day for the last three days about it. DAY 1: "I want some more 4E", DAY 2: "I've got the shakes, need more 4E", and DAY 3: "When does 4E come out?").
Much of the positivity probably has to do with the fact that i sent out a blanket invitation to the Demo, so those that showed up to play in it were likely the ones that already had an inclination to embrace the new rules. I'm sure that if i forced the Demo upon those friends that haven't come over willingly, i would probably get less positive results.
To CleverNickName: Don't give up, try it again with some folks who seem more positive or at least unaligned.