Axilrod said:
+1 on no 24-70 II/5DIII kit. There is going to be so much demand for that lens there is no way Canon will be compelled to discount it.
Right, it'll be years before there is meaningful discounting on the 24-70II. After a number of disappointing 24-70 Mk1 lenses I bought a 24-105 a couple of years ago to see me through until the new lens ships. Surprise surprise!
The 24-105 leaves all four of my 24-70 lenses gasping for respectability. It's a 10/10 keeper. Most people are highly satisfied with the 24-105. Just dig around on this list for positive feedback.
As TrumpetPower suggested, go straight out and pick up a kit 5D3 and 24-105 today. You'll love it. And if in the unlikely event the 24-105 turns out to be unsuitable, you'll barely lose a penny on it if you on-sell. Great lenses like this hold their value.
-PW