I think in the Hybrid versus two-form factor discussion, Nintendo might be able to have their cake and eat it too.
What if the NX Handheld was close to what Eurogamer described, and could dock to a TV if so desired at little to minor graphical bump? Then the NX Console was a beefier version of the exact same, but could play the exact same game media at higher resolutions?
You don't need to force a handheld-console hybrid to do two different things well, it might end up doing neither (power for a console experience being a counter-force to longer battery life). It's one of the reasons the rumors about an actively-cooled Devkit sounds so crazy, why are you overclocking a Tegra X1? You can't stick fans in a portable handheld! And if you go with a Tegra X2, aren't you increasing the price above mass market? And can you get enough power from the Tegra X2 to make a powerful experience when the hybrid is in console mode while making sure it can still down-power for handheld mode?
Instead, have two distinct products, different form factors that play the exact same game so you get the expanded unified library, but with a really great handheld that downscales visuals with a cheaper processor (Maybe a die-shrunk Tegra X1?) and a beefy console that upscales visuals (with a Tegra X1.5 or Tegra 2?). That would explain the overclocked Tegra X1 dev kit rumors, the dev kit would HAVE to be able to do console level development, and then just downscale to Handheld for the "handheld" mode of the game. Nintendo would even double dip with consumers like me who would want both even though I wouldn't actually need both.
Now, maybe the "NX Console" takes a slightly different form, like a "Super Dock" as opposed to the simple no-improvement dock that comes with the handheld. Or maybe the Handheld launches first, and the Console/SuperDock comes to market 6 months later?
Still, the advantage of committing to two distinct form factors is that each can do its natural purpose better, but if they play the same media and share the exact same game carts, then they continue to reap all the benefits of a single "Hybrid" (focused development, combined library).
I personally find a single Monolithic Hybrid less interesting than games that I can take from my Handheld, plug into my Console, keep gaming on TV, and plug back into my Handheld to continue gaming on the Go. It even makes sense because the saved games will be on the Game Cartridge itself!