One of the things I heard at WWDC is that the new Photos app for Mac was started under the name “iPhoto X”. I think they abandoned that name because it carried too much baggage. The whole situation had gotten too complicated. iPhoto for iOS was ambitious but ultimately a failure — too complicated, too fiddly.
Post-WWDC, the way I hope Photos for Mac plays out is not that Apple offers a “pro” upgrade, but rather that extensions allow for third-party developers to improve image editing in Photos for Mac in a similar way to how they will for Photos on iOS. Photos for Mac will likely never be a true professional tool like Aperture was or Lightroom is, but it could be much, much more than a simple library. It could — and should — be something that works well for serious enthusiasts (a.k.a. “prosumers”) in a way that iPhoto never did.
As usual John Gruber has managed to squeeze in two paragraphs what Apple users need. iPhoto for iOS is a mess, its workflows confusing and there’s not real seamless two-way communication with the OS X version.
The idea that Photos app for OS X Yosemite is going to be a prosumer software is very appealing.