Sure, there is a 47W i7-4960HQ in rMBP which has significantly higher power consumption than what I am looking for. If you look at low power U versions of i5 and i7, they seem almost identical (with i7 having larger cache and a bit higher frequency; both are dual core and have hyperthreading). In desktop, you can see i5 is without HT contrary to i7.

If Broadwell can bring 20W quadcore i5/i7 - that would be even better! Currently only BayTrail Pentium J can offer that.