Gizmodo points to the review of the Kata R-102 photo rucksack at Shuttertalk. This one cool bag to consider for $125 USD.
I am currently using Vidpro VID 100 Durahyde Video/Photo/Digital Camera Bag ($34 USD), which I find very comfortable and big enough for all my gear. I don’t have that much of it yet though, but there is plenty of space still. I doubt thought that it will suffecient for two cameras plus lenses and flash units. When that time comes, I’ll be looking towards waht Kata has to offer.
Thanks for linking to Shuttertalk! It’s a very nice bag indeed. According to Kata, there’s a model coming out with space for a laptop too. :D
[1] Now these are excellent news indeed! :)