The best bag I've found so far that works well for longhaul costs only about £43 from Costco of all places, and is made by the same fols that make Swiss Army knives.
1. Has wheels
2. One section ideal for duty free/bunk gear
3. padded laptop section (it may have had a laptop case with it, but I don't use it) also various side nets for wifi/psp etc
4. fan-fold section for maps/files etc
5. usual pen/passport section, with a clip for your keys, pda storage, phone pouch, usb memory stick etc
6. section for in flight hygiene kit
7. Another section for luggage tags etc
Highly commended