For good ways to lighten up a tourer, I'd recommend:
1) 32 spoke wheels, with double butted spokes and alloy nipples. These spoke aren't weaker but give you lighter rotational mass. Lace em up to some Open Pro rims or an asymetric rim (for less dish) for a nice balance of durability and weight. You can replace the spoke easily and you could likely make it to the next rest stop if you were down a spoke or two.
2) Lighter cranks, cassette, and pedals. Lighting up a part that you have to spin over and over just makes sense. For touring application - lighter for these parts won't affect durability (unless you got to extemes). Think SRAM 980 cassette, XT/Ultegra/Centaur level or better cranks and Eggbeater SL pedals - you'd be amazed how much weigh can be saved.
Lightening up the gear which you take along is a whole other forum. Ultralight camping gear is one of the fastest growing segments in the outdoor goods sector and there's a ton of knowledge, ideas and options out there. Once you try it, those 45kg loaded bohemith tourers will start to look like dinosaurs.