Exodus is an awesome name, but you might have to do a couple things to the pack to increase it's "cool factor" so it would live up to that name, such as only having the pack available in all black, with red trim, with chromed hardware. Like someone said, a pack called the ARK had better be ginormous and waterproof or it will be a little confusing to people why you named it that. Similarly, I initially thought the Zip was a panel loader, so maybe go easy on the misnomers unless in fact the new pack will be Ark-sized..
A waterproof UL pack would be pretty cool, though. I don't know if there's seam tape for silnylon, but it would be nice to be able to dispense with pack covers and liners..
For improvements to the Zip, you might give the option of built-in hipbelt pockets. I know you have accessory hip belt pockets available, but it seems like there's an extra layer of fabric with a system like that.