I do like the look and size of the MacBook, but low end dual core won't do it for me right now. It will be interesting to see how the larger market accepts it. I'll definitely be interested once they get a quad in there. I'm on a ivy-b MacBook Pro, so something a bit slimmer would be nice.
I was able to catch the press conference last night and I'm starting to see their vision a bit better now. I definitely agree that the Air's days are numbered.
FWIW, The performance on the basic model is supposed to be pretty decent, benchmarks have it on par with a mid-2011 i7 MBA, which happens the be the very same MBA I use as my daily driver. I have no performance issues with my machine, though I admittedly don't ask it to do too much.
Some of the goons at SA Forums were talking about this and suggesting that Apple is getting the top binned Core-M chips from Intel, so performance is better than what you might expect based on specs alone. One of them tried one out at an Apple store and opened a bunch of apps and Safari windows and such and said it never really slowed down.
Also, the optioned model with the faster processor is supposed to give it a substantial (~10%) performance bump.
Quad is unlikely to come any time soon IMO. But it won't matter to 95% looking at the MacBook. The ports are a much more important consideration. I suspect Apple will give in and add another port of some sort to the next gen.
To 95%? I rarely plug anything into my MBA, use the cloud for most things. There really is nothing else like the MacBook on the market today. I'd get one except for the $1,300 price tag. But there are plenty of people out there not as poor as me so...