I suggest the Canon 17-55 f2.8 IS, it is a great standard zoom with top notch image quality, fast f2.8, and IS. No other lens can match it. I love mine.
If, or when, you eventually and maybe one day do go to full frame, sell the 17-55 used for a good price (and rue the fact that nothing in FF can replace it!).
Remember, the 24-70 won't have any wide angle in its zoom range on your crop sensor camera. If that's your goal, OK, but if you want a wide-to-tele zoom the best options are the 15-85 (overall) or the 17-55 (if f2,8 constant aperture is useful to you).
The 24-70 is not a good focal range on a crop sensor (38-112mm equiv) if you are looking for a bit of wide and a bit of tele in the one lens. This is a 1kg lens with no IS and no natural role on a crop sensor.
I have the 17-55. I also have the 10-22 and it is reserved for extra wide jobs. Which is its best role. It doesn't stand up to the 17-55 for wide angle jobs in terms of IQ (and I mean an *obvious* difference, the difference between damn fine and just superb) and the IS and f2.8 just make it a superb all-purpose lens.
I would be a bit miffed if I had the 24-70 or 24-105 and had to change to the 10-22 for *all* wide angle work.
When I do a wedding I just take the 17-55. Equivalent to 28-90mm. So flexible and just shockingly good. Portraits - covered. Group shots - covered. Indoor group shots - covered (if you need wider you are going to have distorted faces near the edges). Natural lighting indoors with IS - covered. It is *sooo* empowering to simply not think about it.