Adobe Carousel is available in the Mac App Store and the iTunes Store. It strikes me as Apple's PhotoStream on steroids. Sync photos, apply presets (or edit manually,) and share them.
Of course, I'll try the 30-day demo... But I'm just not seeing the point of having yet another photo app. Maybe down the road if it integrates with Lightroom it will become more useful, but for now, $60 a year just to do what I can already do with a handful of other apps doesn't make sense to me.