I've a mate who worked the cruise ships for 18 months, 2xEOS-3 bodies and 10 rolls of 36exp each body per night, 5 nights a week, 48 weeks a year. Plus I don't know how many rolls for weddings etc. in the intervening 10 years or so... Probably both around 140,000+ shots.
They're both as sweet as a nut, albeit worn a little smooth on the grips etc. and I'm sure they'll be fine for a while yet.
With that kind of longevity from a late 90's design, I'm not exactly worried about using my 7D to the full

It's not as if I do motorsports, or stuff where I'm machine-gunning it anyway. It's nice however to get 3 shots in rapid-fire on landscapes if I'm using auto-bracketing for HDR for example.