24-70 IS f4
24-70 IS f2.8
I was saying the same thing in my post (we must have been writing simultaneously) -- this is worth sizing up. Looking at B&H (incl. rebates):
70-200 F/4 $629 (<-- an absolute bargain like the 17-40L is)
70-200 F/4 IS $1,099
70-200 F/2.8 $1,299
70-200 F/28 IS II $2,099
Extrapolating this to the 24-70, this might look like:
24-70 F/4 $1,099?
24-70 F/4 IS $1,999?
24-70 F/2.8 (II) $2,299 (<--- this one exists for sale today)
24-70 F/2.8 IS $3k+? Rare stamps? Left testicle?
And if such estimates are even close, who would buy the first two on that list when the 24-105 F/4 IS is widely available in the $950 range? (actually less, given all the kit+body lens resellers). I'm not buying it.
So I'm going to dismiss the four price points and think that this must be either a value
sell. This new F/4L IS needs to be very small/light or value priced like the 17-40 or 70-200 F/4 NON-IS to make sense.
...or Canon really is nuts.