I agree with Guy here. You MUST have a back-up plan and know the kit you have ( including the backup kit ) pretty much inside out.
Before I shot my first wedding I'd probably already spent way over £8k on kit ( excluding several hundred on good brand [lexar] memory cards) I've since bought a few extra bits and still don't consider myself fully covered as I only have 3 flashguns and use them off camera a lot of the time and only 2 bodies.
I actually met a couple recently looking for a photographer and happened to mention the amount of kit I have, they were shocked at first, then booked me a few days later. They'd actually phoned every one of the togs they were interested in, and asked them about kit and insurance and what they'd do in the event that it all went pete tong. Needless to say my original point of " I always have a credit card available with enough credit on it to purchase *in full* my entire kit should I have a total loss" seemed to help too
Edit: And on another point, I have a backup credit card too just in case
Although that's probably going too far on the safe side.
Pete