My first impressions are based upon some time playing with the new MacBook in my local Retail Store. I'm not in the market to buy new as I got married earlier this year and am therefore flat broke! My 2 year old white C2D MacBook will have to suffice for another year but that's no big deal as it does its job quite nicely although I have suffered with the famous falling-to-pieces-plastic on my MacBook.
The Design & build
I know that it's not everybody's cup of tea but I actually like the new design; it feels tougher than the old plastic Macbooks (obviously - its metal!

) and both the body and the screen feel rigid and strong. The black/silver colour looks cool and I actually like the keyboard layout (I may be the only person who does - perhaps I should be drugs tested...).
Trackpad
Interesting. My initial fear was that I would find the buttonless design difficult to use but, in fact, I was able to start using the track pad in my normal way i.e. clicking with my thumb whilst tracking with my index-finger. I tried using my index-finger to both track and click and it felt a little wierd at first.
I don't have access to even three fingered gestures but, having tried them and the four fingered ones, I like them.
Screen
Okay... *puts helmet on and takes cover* ... I like the glossy screens (I like the one on my current MacBook). Under the lights of the Retail Store, there was very little reflection and the display was bright, punchy, easilly readable and most useable. I don't know what it would be like in bright sunshine but I'd be very happy to use one of these in place of my current machine.
However, I can quite understand proffesionals who have complained of not having a matte option. I said above that there was "very little reflection" but I bet a lot of Pros would like "no reflection at all" i.e. a matte screen.
It's a shame that the discussion has descended into a somtimes vitriolic argument about the issue. The I-like-the-glossy brigade have, on occasion, accused the disgruntled Pros of being moaners but, from their point of view, they have a right to be disgruntled. They're not asking to do away with glossy altogether but simply to have the option of a matte screen.
The great Firewire debate
I'm not really qualified to have an opinion on this one - I don't use firewire and so couldn't care less about it not being there. I will say, however, that having a FW400 port on my existing MB has never got in my way so I'm sure I could live with one on the new MBs.
Overall
Nice! The new MB would certainly satisfy my needs. The lower end of the new design would be fine as I have no need of a backlit keyboard (I don't do a lot of typing in the dark). The only BTO I would do is an increased HD capacity.
EDIT: Probably my only concern would be over the durability of the new clickable trackpad - its a new moving part (I know there was a button before but this is different) and so we'll have to wait and see whether Apple's QC is on the ball in this matter
Time to start saving....