It also means unless they crater margins,these parts are not going to be that cheap. The GT3 4C parts I estimated(after look at the pictures),are at around 330MM2 to 350MM2 for the the total die area including cache and around 250MM2 for the GT3 2C parts with L4 cache.
GT2 SB and IB 2C parts are between 121MM2 to 149MM2 in size:
http://www.anandtech.com/show/5875/dual-coregt2-ivy-bridge-die-measured-121mm2
http://www.anandtech.com/show/5771/the-intel-ivy-bridge-core-i7-3770k-review/3
I suspect the 2C GT3 parts will be the ones found in expensive Ultrabooks and the MacBook Air.
There was noise about a GT3 part without L4 cache,which might find its way into cheaper laptops.
Edit!!
The 2C GT3 parts are called ULT which means they will be for Ultrabooks.
Second Edit!!
I expect Next generation Atom to take up the slack in the lower end of the market,meaning the Core based CPUs stay for the middle and higher end markets,and hence Intel can maintain margins.
Third Edit!!
It seems to be around 350MM2 in size:
http://www.anandtech.com/show/6993/intel-iris-pro-5200-graphics-review-core-i74950hq-tested/4
Interestingly the test setup appears to be some sort of desktop.