Very good question - I believe both the CPUs and GPUs used in the latest non-retina MacBook Pros use less power than their predecessors.
You'll have to wait til the proper in-depth reviews come out for these machines, but I'd wager that they have a longer battery life than their predecessors and that Apple probably just isn't marketing them as such as they don't want people seeing this as something these machines have over the Retina models.
It is a good question but only Intel could really answer that well.
From a distance it seems the 22nm process is just quite poor and the 3D gate transistors don't seem to do that great. It already was almost half a year behind schedule. Maybe they need another year to get it right.
The smaller processes get more and more difficult. Before they were really lucky with the 45nm process which just worked out well and with 32nm they did it in steps with the 45+32nm mixed Dual Cores first which gave them quite a bit of testing before they rolled it out on all CPUs.
Those Dual Cores had such a different architecture compared to the former C2D that they weren't really comparable.
Maybe it is wise to give 22nm 6-12 more months to deliver. Maybe Haswell will really show what it can do. Maybe not and smaller process will just get consistently worse.
14nm is still on the roadmap as a fixed goal. With 10 or 8nm they don't even know for sure how it will turn out or if it really works for complex logic. With Flash I once read even the optimists think 6.5nm is about as far as it goes.
With Ivy Bridge they also changed the C0 lowest clock to 1.6Ghz again and the voltages are quite high. Maybe they just want to make look IB look a little worse to make Haswell look better which is supposed to get an integrated Southbridge and many plattform energy savings -> lower idle power.