Originally Posted by what car??
I know this may seem like overkill, I have three cameras traveling with me in Central America currently. I have a Contour mounted to the helmet, a Nikon Coolpix P6000 that fits in my front jacket pocket, and a Canon DSLR with an extra 75-300mm lens (I bought this one in Guatemala, avid Nikon user but couldn't find what I wanted). The Nikon is great for shots that are fairly close and I don't really want to dismount or just want a few shots etc.... But if I find something interesting or far away I do pull out the Canon and use it. Sometimes with the tripod, depending on what I'm shooting. The Canon bag is padded and I have it sitting in the middle of the pannier pretty protected. I do not ride with a tank bag.
Sounds like the perfect set-up to me. My NEX has mostly replaced my DSLR and Point-n-shoot, but having a small camera in your pocket that you can yank ouy and use with gloves is great. Even better if you don't care about the odd scratch. It's also better for wandering around with off the bike in less savory neighborhoods.