No. Because if i wanted a desktop i'd buy a desktop.
13" Macbook Pro is the best compromise size for me. If they can push the screen out to 14" by making the bezel smaller, even better.
I have used many 15" machines in addition to my own 15" MBP classic, and they're just heavier, hotter, and crappier battery life for dubious performance improvement that isn't good enough to make up for the downsides (imho). 17" is just a bigger, heavier 15" machine IMHO - they're even more unwieldy and useless for doing the job of being a portable machine you can use anywhere. Once i get to a desk, i can plug into a monitor and the form factor of the machine becomes irrelevant. Until i get to a desk, 15" or bigger is a pain in the rear.
Also I'm never going to buy another portable with discrete GPU (even if i was to go for a 15"), it's just not worth it. The laws of physics on portables simply guarantee that you're just not going to get desktop class GPU performance. They just don't have the battery or thermal headroom. All you end up with is a "meh" discrete GPU (which might be 'ok' performance wise for the first 12 months of ownership) and worse battery life and heat.
Really hoping for e-GPU to take off, a friend has been using various cards including a titan via thunderbolt for years, it works, just no one really makes a box that works out of the box without hardware hackery.
edit:
I do see the 15" retina being replaced with a machine that has 16" usable screen area, which should be a good enough compromise to replace the 17".