Upload & Sell: On
I used a DryZone 200 for a while, but found it was too awkward for me to easily get gear in and out of when things are happening. Now I use a combination of the following packs and bags, depending on what I expect to encounter.
1. When I want to take a small to moderate amount of gear in really wet conditions, I use a waterproof SealLine Urban Backpack (small, 16L). It's a ruggedized, roll-top dry bag with integral backpack straps. The shoulder straps are decent daypack style, with a simple webbing waist belt. It'll take two pro bodies and three f/2.8 zooms, but it's awkward to have lenses mounted on the bodies while in the bag. (This would not be a problem with the large size version.) I protect lenses with neoprene Op/Tech Snoot Boots and cameras with neoprene LensCoat BodyGuard covers, and just dump them all in the bag (same approach for all of my other bags & packs).
2. For getting a lot of gear to and from a location when there is a real chance of getting it soaked during transit, I use a waterproof Watershed Chattooga Dry Duffel (29L). It's big enough for a TT Airport Commuter, with extra space for a few rain coats and etc. The Chattooga drybags have a clever dry-seal enclosure that's waterproof to about 100m immersion, and it's much easier to open and close than the WP zipper tech used on DryZone packs.
3. For general transportation, I use North Face Base Camp Duffels. I have two; size L(90L), and XS (25L). They're waterproof everywhere except the zippers, which are partially protected by flaps. They're great for unloading gear from a car and putting it in a shelter. I often use MEC pack liners to hold the gear inside the Base Camp duffels, and so the contents are absolutely WP.
One of my most common combinations is the Urban Backpack with XS Base Camp Duffel.
SealLine Urban Backpack http://www.mec.ca/AST/ShopMEC/Packs/WaterproofPacks/PRD~5015-632/sealline-urban-backpack.jsp
Watershed Chatooga http://www.mec.ca/AST/ShopMEC/Packs/WaterproofPacks/PRD~5010-533/watershed-chatooga-dry-duffel.jsp
Base Camp Duffel http://www.thenorthface.com/catalog/ca_ecom/en/sc-gear/equipment-luggage_duffels/base-camp-duffel-large.html
MEC pack liner http://www.mec.ca/AST/ShopMEC/HikingCamping/StuffSacksPillows/PRD~5016-043/mec-pack-liner.jsp