Some saner thoughts on all of this:
https://www.apertureexpert.com/tips/2014/6/27/aperture-dead-long-live-photos#.U6-j3o2wJgV
and
https://www.apertureexpert.com/tips/2014/6/28/comment-follow-demise-aperture#.U6-kHI2wJgU
But my own investigation took me back to the WWDC Keynote, where they demonstrated the simple interface of Photos and offered a peak behind the curtain at the deeper software underneath.
The simple interface has a"Light" slider and a "Color" slider. Want to adjust an image? The software will brighten or darken or saturate or desaturate your image when you adjust that slider. But they showed, without going into too much detail, that these smart adjustments were actually several adjustments made in concert with each other. So making the image brighter with the "Light" slider might actually adjust the exposure up but the highlights down, while boosting shadows and contrast. All handled automagiclally with that one slider and based on the content of the image, to keep it looking good. But you have access to all of those sliders if you want that.
So I looked at the interface of the OSX Photos in the UI still that was released yesterday, and here's what I found:
Under the "Light" slider, you have: Exposure, Highlights, Shadows, Brightness, Contrast, and Blacks.
Under the "Color" slider, you have: Saturation, Contrast, and Cast. Note: this "contrast" is shown having a different value than in the Light heading, leading me to guess that it is color contrast, or what Lightroom calls "Vibrance."
Under the "Black and White" heading, Hue Strength, Neutral Boost, Photo Tone, and Grain.
Definition and Vignette have sliders.
White Balance can be selected ("Neutral Gray" is shown) and Warmth has a slider.
There is also a five point levels tool with a monochrome histogram. This is in addition to the 6-color histogram at the top of the UI.
These are all shown to be the tools in one of four toolsets on the far right of the UI. The other icons are Crop, Band-Aid, and a three-circle Venn Diagram icon ("effects" in iOS iPhoto).
So that's plenty to work with. More than Aperture, in fact.
Reminding myself of the Aperture UI by visiting the product page (I no longer have it installed, having switched to LR years back), the adjustment tools there are:
White Balance ("Natural Gray" selected) with a warmth slider. Identical in Photos.
Exposure, Recovery, Black Point, and Brightness. All but Recovery is in Photos, but Photos has Highlights and Shadows.
Contrast, Definition, Saturation, and Vibrancy: All but Vibrancy is in Photos, but I'm guessing the "Color Contrast" is exactly Vibrancy.
Tint has no obvious analogue in Photos from the still that was released.
So there we go. No guarantee, obviously, but I'm willing to bet that importing an image library from Aperture will see edits transitioned seamlessly, or at least as seamlessly as the move from Aperture 2 to Aperture 3. And haven't people been clamoring for a new, more-feature-rich version of APerture for years now? It seems to be called Photos.