I got a new MacBookPro Retina with 2.3 Ghz, Intel Iris Pro and Nvidia GeForce GT 750 M.
No such heat problems as with my Mid 2012, 2.7 GHz, Intel HD 5000 and Nvidia GeForce GT 650 M.
The main difference:
In opposite to the Mid 2012 MBPR, where the use of the Nvidia 650M slows down the system (instead of increasing performance as expected), the new one dramatically increases performance with the Nvidia GeForce GT 750M up, specially of apps using much graphics power such as FCPX, iPhoto, Aperture etc.
E.g. film editing directly on native H.264 can now be down without the need of optimizing footage before. With the new one it is really fun to work with, the Mid 2012 was definitely not usable.
Absolutely no heat issue with the MBPR late 2013.
I assume there must be A LOT of Mid 2012 MBPR 15 out, having this heat problem and Apple does everything to avoid a product recall of all faulty MBPRs. What is in fact really poor by Apple.