Well, I guess I found the downside of being undecisive about buying the books and preording at the last minute. Looking at the Amazon page, my copy won't be shipped until July 22nd, Delivery estimate: August 15, 2008 - September 5, 2008.
They must have underestimated demand, and (rightfully) must ship out by order date. My friends copy shipped on the release day.
We did get one copy locally, and did give the adventure a run through with the prebuild characters. Based on everything we saw and did, I like the changes. The game really has been streamlined a lot. Many things I hated in early versions, and a number of things I didn't realise I hated have been stripped away. Combat is more fluid and the characters have been rebalanced and increased at early levels. Lots more health then before, but just as vulnerable (losing 3/4 health in one round was possible, but the quick heals and effective taunts mean the rest of the party can remove the danger effectivily).
I do have some mild concerns that the damage you deal may not scale well with levels (we got to lvl 3 in one day. 3 encounters). It looks like the ability to resist damage will grow as the creatures and you do, but the damage from the core abilities does not. This could lead to long endurance fights and slow down the gameplay in general. However I havn't yet read the core rules, so will have to reserve judgement on that. There might be some mechanics I havn't yet seen.