I am optimistic only because when just using a bit of arithmetic, and unfortunately cherry-picking Geekbench, there is reason to believe that Denver could be the real deal. Intel certainly has been around way longer, but also keep in mind they also license technology from Nvidia, and Nvidia's GPU department is second-to-none (though AMD is for sure making a nice comeback, albeit with small R&D levels). Nvidia has said they have been working on Denver for 5 years, so obviously there has been a lot of effort, I won't be surprised if its competitive.
I'm going to use Geekbench single-thread again because I don't have another choice.
If TK1-32bit is putting out 20% more performance than T4, we're around 1100 points, a smidgen higher than the A7 at 32bit, so nothing fantastic about that. But TK1-32 has 4 cores not 2. Logically, in order for the dual-core TK1-64bit/Denver to perform at the same as the TK1-32 it must have double the 32-bit ST performance. So that doesn't even include the added 64-bit benefit. I don't see any reason why Denver at 28nm can't put out around at least 2000 points in ST, and around 4000 in MT.
I don't think any of this is too optimistic, it makes sense. I'm not sure if there is a 100% scaling effect from 4 to 2 cores in ST, but it would make sense that it those 2 cores have to do twice the amount of work as the 4 to achieve similar performance (32-bit).
It doesn't seem impossible that Denver at 28nm could compete against Haswell-Y. Broadwell-Y is sacrificing a lot of performance to get to 4.5W for TDP, so while Denver may not be on par with Broadwell-Y 4.5W, it could be nearby, especially as a first architecture iteration. If Denver were on 20nm, it's possible that it would beat Broadwell-Y.
Remember too though, I said the Denver uArch + 16FF+ would put out i7-U performance, particularly Haswell which gets around 3000 ST points for the i7-4600U. If we use that 2000 pt. number for right now, an extra 50% yields 3000, and again this is 32-bit not even 64.