My new Dell Inspiron 8600 doesn’t come close to fitting in my classic Tumi Organizer Computer Briefpack. Once upon a time I suggested that a laptop that doesn’t fit in a Tumi Briefpack should be sent back, but… the laptop landscape appears to have changed dramatically since that last time that I owned one. Today a 15″ laptop weighing 6.5lbs is considered “thin and light”, and you’d have a rough time finding any laptop at a retail store for under $2000 that would fit in my old Tumi (newer ones appear to have more accomodating laptop sleeves).
So I’m in need of a new backpack. According to Dell, the Inspiron 8600 measures in at 14.22 x 10.79 x 1.52 inches. Ideally my new bag should have enough room for my Speeze “Metal Gear Box” USB2/Firewire enclosure at 9.75 x 5 x 1.25 inches, power supplies for both, a 6 x 6 x 1.25 inch CD case (or integrated CD storage), a half-dozen cables, and the usual briefcase stuff (checkbook, passport, business cards, notepad, files, etc). In a perfect world my new bag would have room left over to carry a Gameboy, Zaurus, large Oakley sunglass case, toiletry kit, spare socks and underwear, and two paperback novels for light travel duty, but I’m willing to compromise in that area.
I’d like to keep this around $200, but I could go double that for something that genuinely matches the versatility of a Tumi Briefpack. Current Tumi products need not apply; I don’t care for the t-tech line, and the couple of other models that fit my laptop do not meet my other needs.

Are you specifically looking for a traditional backpack? I picked up a Timbuktu messenger bag not so long ago and have found it to be the cat’s meow. They’ve got extra goodies like laptop sleeves and cell-phone/sunglasses cases and are a lot more comfortable and secure than single-shouldering a backpack, especially when loaded down. The downsides are that there’s a cross-the-front strap that either needs to be done up or tucked away and they dont zipper shut, so if you tuck it under the seat in front of you, items might roll out.