Except for the leaked benchmarks.
And the fact that buys aren't comparing desktops to laptops because those comparisons are apples to oranges, no pun intended.
And the fact that iGPUs are where the industry is going.
And the fact that most consumers don't even know what's faster, but rather will just go with the marketing hype.
All valid points to be sure. But I don't think Apple is ready to ween the dGPU buyers just yet. They've typically laid out a path to discontinue components and perceived features gracefully. (Hence the availability of the cMBP's).
Perhaps the dGPU will be a BTO option this time but it will be there. So nope, Cold Turkey is too harsh a punishment this round - even for Apple. What people should be thinking about is what their next 15" laptop will look like after Haswell.