I had an interesting experience with the 7D last week: I had just boarded one of the GWS cage diving boats in Kleinbaai, South Africa, and was standing on deck with my 7D hanging behind me on the strap (the 5D was housed and ready to go). As the boat on its trailer was reversed down the slipway, a load of water tipped off the top deck and directly onto my 7D and lens. I didn't even notice it was happening for a few seconds. I reckon about half a litre of water had been tipped on it. First thing I did was taste the water. Luckily it was fresh- must have been rainwater. I gave the camera and lens a quick swab-down with my t-shirt and it's been fine since (touch wood!). Luckily it was the 17-40 which is also weather sealed.
In fact it had a bit of a hammering in general in SA what with wind-blown sand and salt spray and has come through completely unscathed.
I had a slightly more disconcerting experience with my 7D
I took it out in rain last week under the protection of an umbrella. A heavy downpour forced me to carry it under my slightly damp T-shirt for about 30 minutes but the camera never got wet.
In the car I noticed that the LCD screen (menu button and live mode) and AF was not working. I checked and replaced the battery, removed/replaced the card and placed it infront of a fan for a while. No go.
I was gearing myself up to see how Canon would handle this situation. They don't warranty moisture damage but given that the camera never physically had water on and is supposed to have "environmental seals" I thought that I had a pretty good case.
As a last resort I placed the camera in my kitchen oven overnight (turned off). The next morning everything worked and its been a joy to use ever since...but never again in the rain.