I like the look of this a lot.
I was almost about to buy the 6D with the 24-105mm f/4 but now I'm thinking 70D with EFS 15-85mm f/3.5-5.6.......or maybe get myself a 17-40 mm which would be a 27-64mm equivalent walkaround.
This changes things somewhat!
I like the specs. The two things that put me off the 6D are the AF and no built in flash. I don't much want a pop up flash but would like an integrated speedlite transmitter.
I was about to do exactly the same as you and bite the bullet on a 6d with the 24-105, but the 70d spec is a real spanner in the works. Provided the price is substantially cheaper than the 7d, which you can now get for around £700 for the body, it'll be a very good deal.
The flash is no worries - if the 70d can perform anywhere near the 6d at high ISO's it'll be more than adequate. On the other hand, the wifi on the 6d and now 70d is an extremely compelling selling point for me - I've been doing astrophotography with an rx100 (don't laugh - it's amazing what one can achieve with that pocket rocket!) and the idea of using a phone as a remote is really nice.
Lenses wise, I'll take the cheapest possible kit EF-S lens going for when I need the wide, and I'm still thinking I'll get the 24-105L, the 40mm pancake and a 70-300 - all EF. I'm not interested in pricey EF-S lenses at all because at some point I can see a full frame body being purchased - I'd rather buy EF lenses and deal with the scale factor.
If I can get all that for say £1600 (about $2400) - which might be possible with grey imports, than that's quite a kit. Is it necessary to spend another £500/$800 for the 6d? Probably not. I expect the 7dmk2 when it's announced will be more costly than the 6d - and I'd definitely rather have the 6d then a crop body at that sort of price.
Anyway, it's all speculation - let's see what the reviews say first.