Though I've posted on this thread already, I think my travel kit has changed since then, primarily due to the addition of a GF-1 which kind of acts like a zoom alongside my Canon system.
It would be:
GF-1 + 20mm 1.7
5DII +
Nikon 28 2.8 or Leica 35mm (depending whether I expect to shoot more portraits or landscapes)
Olympus 90mm Macro or Contax 85mm 2.8
+ EOS-M4/3 adapter
In reality, I'll take a couple of other lenses - an Oly 21mm 2.0 and a Voigtlander 180mm - but I won't carry them all with me at any one time. I'm going to Burma and the Middle East for 5 months on my way to live in Berlin this year, and this is the kit I'll take. I have no qualms about leaving a few lenses in a locked bag in a hotel room - I'm pretty careful. Maybe even a Contax G 45 and a Panasonic 14-45 for AF, too.
Zuiko Digital 9-18mm zoom
Panny G20/1.7
Zuiko OM50/2 Macro
= a total of 1.4 kg
The 5DMkII had to go, now the travel kit weights nothing. All the bits in the same Domke Satchel. The OM50/2 Macro will be replaced with a Voigtländer 75/2.5 and a Voigtländer 50/1.5 where the later will be used at home and the 75mm for traveling, I think. The exact details are always decided just before its time to take off.