Dark Sky would've added more value if they'd just renamed it Weather and made it the built-in app, and yet...
I do hope they'll offer Pixelmator as an included app on Macs and Pixelmator Pro alongside Logic, Finalcut, and other "Pro" software. The lack of a built-in image editor can be annoying.
Photos works for some stuff, Preview includes basic adjustments too, but sometimes you just want something like a hue/saturation adjustment instead of color temperature and pink/green tint, or multiple layers so you can experiment with different edits non-destructively.