Maybe these are the guys I need to make the backpack of *my* dreams. I'm currently using a Crumpler Customary Barge, which is good, but not quite there.
I'm looking for an air-travel pack. I want space for two bodies (a D3 plus a D300, and I sure Canon people have an equivalent); space for three fast pro zooms, or four fast primes plus a 1.4 extender, or some mixture of those. Space for the usual odds 'n ends: cleaning kit, memory card vaults, couple of extra batteries and charger.
A laptop sleeve, and pockets for the power supply, power cable and a ten- or twelve-foot Ethernet cable.
And (this is the critical part, that you can't get anywhere): a large dedicated top section for travel gear. By travel gear I mean personal prescription medicine, a jacket, a paperback or two, extra pair of glasses, notebook, pens, chapstick, cell phone pocket, iPod pocket, earphones, etc.
This all has to fit in a bag that is (itself) both light and small enough to fit in overhead bins. I know it's possible, because I went to Iraq with that kit packed in a Blackhawk tactical bag made for medical gear. The problem was that there's lots of useless stuff in the bag (from a photography perspective) and that makes it heavy -- 7-8 pounds on my bathroom scale.
For a travel bag, you're looking for the ability to fit in any overhead, and then carry a lot of stuff a short distance: not a technical pack made for long hikes, but a tote sack made with photography in mind. I found that I did not want a rolling case, because even you're in a city, a rolling case is often awkward; you need to be able to put it on your back. My bags now always have a carabiner on the tote strap, which can be clipped to my rolling bag any time I'm inside an airport or moving both bags on hard surfaces; but much of the time, our of doors, it's easier to carry it.
I tried sending some suggestions to Think Tank, and they thanked me politely -- and continued making bags which would allow somebody to carry 50 pounds of photo equipment onto a airplane, but not even an extra jacket. For most people traveling long distance, this extra stuff is critical -- especially things like prescription medicines and glasses; and anybody who flies internationally knows that you can always use space for stuff like earphones and iPods, especially if you wish to maintain your sanity.
JC