Depending on the length of the trip & other considerations (e.g., how much time there will be for serious shooting, how much strenuous physical activity will be involved, etc.), I will typically bring either 2 bodies, each w/a different lens, or 3 bodies, each w/a different lens. Nowadays, @ least 1 of the bodies will be the M8. Similar to Tom A, my lenses will vary depending on environment (e.g., more wides for crowded cities, maybe a telephoto for open spaces), but I always have @ least 1 50mm (or normal equivalent on the M8, usually the 35/1.4 'lux ASPH).
If I have the luxury of not doing too much heavy lifting, I may also bring along a medium format folder or TLR, a "novelty" camera like a Pen F, or even just an "exotic"/specialty lens (e.g., Noctilux). I also recently picked up some high-end point & shoots (Natura S, 28Ti, etc.), so I may put some of them into the rotation for future travels.