If you're planning on buying it anyway, and don't plan on waiting in line at the Apple store the day it comes out, maybe you'd like to buy it at Amazon and throw us a referral? They've set up a special landing page for you to get all the details - right over here (The W at Amazon).
Keep in mind this'll only work on Intels - if you have a PowerPC, you're stuck at 10.5 (and probably need to think about upgrading some time in the next 24 months).
We're looking to purchase another laptop for the family and wondered if there is something specific I should watch out for and insist on having on this machine. We've been looking at Dell Vestro 3550 series.