Absolutely, and I certainly don't want to come off as biased against it. IMHO the D750 means Canon should drop the price on the 5D3 until the 5D4 is available.
It will be interesting to see what happens with 5D3 pricing. For someone who isn't heavily invested in either system, I don't see any incentive to purchase a 5D3 over a D750. If someone who isn't heavily invested in either system asked for my opinion regarding both bodies, I'd tell them both are great tools, but the D750 clearly offers more value for the dollar.
These products are similar, but the price of one has little to do with the price of the other. That's because they're not easily interchangeable. Each is attached to a complex system, and that system is at least as important as the body. The incentive to purchase a 5D3 (or 6D) over a D750 is still connected to the system behind it, the unique lenses, the ergonomics, the service, etc.