I'm in the exact same boat as I too want to make a macbook purchase but have been holding out for leopard. The rumors floating around of course attract my attention not for size but for possible "touchpad" changes etc.
Whats available right now is perfect for my usage,both for browsing and school related activity. I love the shop and the screen size being 1' bigger than what I am using right now in my dell 700m is perfect, an extra inch of screen real estate would be great.
I don't know if its worth holding out because I'm ok with whats available, sans leopard for the moment. I really want to purchase before the holiday season but without concrete information as to what is coming and when its going to be tough for all of us to make a purchase.
I suppose at some point I may just pull the trigger and buy something and if something great comes out a few months later I'll just ask apple for a gift card, haha just kidding.
OP...I feel your pain, let me know what you decide.