So many insane comments here.
You need the GPU for almost anything, most of the stuff somebody who buys an MBP will include heavy GPU intensive work.
And no, there will be no dedicated GPU in the 13 inch MBP. It makes absolutely no sense whatsoever. That computer, just like literally any other that is comparable in size (or even larger) does not have dedicated GPUs. Nor the thermal performance of these GPUs, nor their power consumptions are compatible with the size of a 13 inch ultrabook. This has been like that for years.
I would argue that a good eGPU case is a much better solution, as any dedicated mobile GPU will be soldered to the MB, will be a dumbed down version of a desktop one, eat the battery and will act as a personal lap radiator. Also, GPUs get obsolete at a lot faster rate than CPUs.