I looked into this too, If you go to the Adobe homepage you can view some products you may use such as Dreamweaver, Flash, Photoshop etc, if you browse the software you are going to use, you can see "System requirements" for each product, This should help you narrow down your short list of laptops.
I also looked into Macbook and macbook pro "New intel dual core 2" if you google search for "test macbook photoshop CS3" and Macbook Pro you can see also that having lots of memory 3GB plus cuts down time while using the software from 15 to 50%! as opposed to 2 GB!!