I got an early look at Photos, Apple's replacement for iPhoto and Aperture. I like it — it's fast.
Photos for OS X uses some other neat organizational tricks. The Albums view automatically highlights photos from your last import and your favorites, along with buckets for different kinds of images: panoramas, slo-mo videos, and time lapses, for example. On the whole it’s a much easier system to navigate. And since the software is completely brand new, it’s super fast, even with a large library of photos — at least, it was on the new MacBook Pro we tested it on.
Much more useful than my post is Josh Lowensohn and Nathan Ingraham's look at everything you need to know about Apple's new photo software and services.