I don't know if bringing back this architect is going to change much to be honest.
Nehalem was decent but not fantastic. IPC was better than like Conroe, sure. But their first attempt at an IMC baked onto the CPU was a bit "half baked" since they were pretty weak. Also the core voltage was tied to the memory voltage, so overclocking your CPU could cause you to overvolt the already weaker imc.
Plus, as already said, the issue isn't design, its the node.
I would say a lot of the reason I don't think Nehalem was very good was what came after it. My PFP is an Bloomfield system with an i7 940 and X58 sabretooth. Compared to my i5 2500k system, the 940 is honestly worse, despite the hyperthreading support. The IPC is noticeably worse, and the i7 940 does not overclock anywhere close to as high as my 2500k. Now an i7 980X vs a 2500k, that would be an interesting comparison...