Naneu Pro is the only company that makes a dedicated backpacking photo pack, its called the K5. I was one of their testers. They use an old internal backpack design and some old style materials, but it is by far the most comfortable "camera pack" around. Its good for overnight trips or multiday trips in a warm climate. I am waiting for an expedition version with some lighter weight, more modern materials.
So if you want a true backpacking camera bag, this is your only real option. Though I still use small camera bags inside my backpack for long trips. The K5 isn't good if you have big glass.
I couldn't believe it when MountainSmith came out with their line, they have the background in backpacks, but just made the same design as everyone else had.
Funny thing about Naneu Pro, I don't they have ever backpacked in their life, but they made the first real backpacking camera bag.