Along vaguely similar lines, in June, we headed off (as usual) to Crete for 2 weeks, me armed with the SLR kit (only 1 body) and a vague plan as to what I'd like to shoot. Due to my illness at the time (all sorted now), I had no energy, balance or inclination to do any of the things I had vaguely planned - in fact, I carried the bloody kit around for 14 days and took the grand total of 1 (one) shot! I've always made it a rule that if I take a piece of kit on holiday and don't use it, it stays at home the next time we go, so I'm not allowing myself to take the SLR kit next year! Instead, I've bought myself a bridge (Fuji HS30) and a couple of compacts (both Fujis, an XF1 and an X10) which all together weigh less (and take up less space) than the D700 and 2 lenses.
I'm allowing myself to break the rule of "use it or lose it" a bit - I didn't use my snorkel, flippers and mask this year but I'm pretty sure that to have done so would have been dangerous (possibly even fatal...) so I'm allowed to take them next year! If I was being strict, I would simply buy another set of snorkelling kit there anyway, so my rule bending will save me a few pennies.