The PS4 Pro, as explained by the man who designed it

First, the Pro doesn't signal the end of video game console generations, even though its specs and launch window fit a pattern that resembles PC or smartphone upgrade cycles more than traditional console releases. Second, the Pro is valuable even if you don't have a 4K TV. Third, though most games on the Pro won't actually be rendered in true 4K, they're still much improved over the standard PS4. Sony probably feels the need to clarify these points because after it revealed the PS4 Pro in September, there was some confusion over the capabilities and identity of the new console. It was pitched as a mid-generation upgrade that would usher in an era of 4K gaming, but after the scripted presentation, it became obvious that 4K was still out of reach for most developers.