A 'kit lens' bundled with a body always covers the 'general purpose' range, meaning at least moderate wide angle to short telephoto. That's why you won't see an APS-C kit with the 24-105mm - 24mm on APS-C is 'normal', not wide angle.
No, I'm aware of that. I'd love to take a 15-85. But I want to keep my lenses flexible. I just don't wanna buy an EFS lense, even with a crop cam. I don't want to regret buying a lense, if I go full frame one time...
Personally, I don't get the idea of buying a lens that's suboptimal for the camera you have, and optimal for a camera you don't have, but *might* get, someday. It's like getting your kid hiking boots two sizes bigger than their feet - sure, they'll grow into them - but there will be a lot of blisters first.
On the same APS-C body, both the EF-S 17-55mm f/2.8 IS and the EF-S 15-85mm f/3.5-5.6 IS outperform the 24-105mm f/4L IS. The only real rationale I can see for the 24-105mm is if you have a 7D and require weather sealing. Even so, you'd want either an EF-S 10-22mm, one of the EF-S zooms listed above, or an equivalent, to cover the wide end. I find that the 24-105mm focal range on my 7D works decently outdoors (as long as I'm not trying to shoot wide landscapes), and not well at all indoors. On the 5DII, on the other hand, the 24-105mm focal range is excellent for general purpose use.
The high-end EF-S lenses hold their value quite well - for example, after buying a new EF-S 10-22mm and using it for about a year, I got a 5DII and 16-35mm II, so I sold the EF-S UWA zoom - for $50 less than I paid for it (and that was before the prices jumped earlier this year - today, I could have sold it for a profit).
I'd really recommend considering the EF-S 17-55mm f/2.8 IS or the EF-S 15-85mm f/3.5-5.6 IS, and if you go full frame someday, sell it.