I think it is a save bet that almost all of the dual core higher end chips will come in GT3. Only the i5, i3 will use the lower end models. Also on the quad core chips like what goes into 15" and bigger they probably won't add a GT3 as those can rely on a dedicated GPU anyway and a 650M will stay quite a bit faster.
The real problem with Haswell is the on die memory. Apparently it will be some upto 128mb and with many variants with less than that or none at all.
GT3 will have so much compute power than the standard DDR3 system memory will probably not keep up and feed those ressources. Only with the max amount of on die memory can it really deliver.
So it is not just GT3 but also the onboard DRAM.
Again I think that quad cores in the big notebooks probably won't have any of that stuff. Yet 13" rMBP, MBP and Air should all come with the best GT3 variant Intel will offer. Maybe the 13" MBP has a default config with a worse chip but all the others shouldn't. The Air just for the power savings the onboard memory will give.