I agree with Mike - what you put in your survival kit depends on what you expect you'll need it for.

What are you worried about? The "OhmigodtheydroppedtheBomb" scenario, or a "Gee, that's funny - I could have sworn the carpark was just over this ridge" scenario?

If you're backpacking, then everything you carry is, en effet, part of your survival kit. Why do you need a specific kit in your rucksack? If you want a smaller kit that you can clip onto your belt for short side trips (just in case the weather turns nasty and you can't find your way back), that's one thing. If you want a kit that you'll still have with you when you fall into the river and jettison your main pack, then you obviously don't want the SK to be in that pack.

Remember, you have to carry all this stuff. Any unnecessary "junk" you stick in there is dead weight. Sure, a SAM splint (as one poster suggested) would be nice to have, but how necessary is it? I'd prefer to take the equivalent weight in protein bars and jury-rig a splint from tree-branches or a packframe, if necessary.