Apple today released the first preview of Photos, its iPhoto replacement, to registered developers.

Photos, slated for an official launch later this year, will be offered free to OS X Yosemite users, Apple said in 2014, when it announced the iPhoto substitute would ship in early 2015.

On the Apple website, the Photos timetable was simply "coming this spring."

The revamped OS X application resembles the same-named app on iOS, and replaces iPhoto, the 13-year-old application that has been dissed by many for its awkward interface and confusing connection to the cloud.

iCloud -- Apple's cloud-based storage and synchronization service -- is a key component of Photos, both a potential boon and bust for users.

Something called "iCloud Photo Library" lets users store photographs and videos on Apple's servers, making them available from any of that user's iOS or OS X devices, or from other platforms' via a browser. iCloud will also be used to sync changes to images and for sharing photographs and video with others.

In iOS and OS X, iCloud Photo Library (which is now in beta on iOS), generally leaves lower-resolution images on the local device but stores the full-resolution originals in the cloud.

Although users can enable or disable the cloud-storing feature at will -- retaining all images on the local device; say, their Mac -- those who take the plunge may quickly see their 5GB of free iCloud storage evaporate. Apple's prices, which were reduced last year, currently stand at $0.99 per month ($11.88 annually) for 20GB, $3.99 per month ($47.88) for 200GB, $9.99 per month ($119.88) for 500GB and $19.99 per month ($239.88) for 1TB.

Those prices are higher than some competitors, lower than others, but are least attractive when compared to the 1TB on OneDrive that Microsoft bundles with Office 365 subscriptions (as low as $69.99 annually for consumers) and the free 1TB on Google Drive that Google has at times handed out to Chromebook buyers.

Previously, analysts have described Apple's cloud storage strategy as focused on building a better experience in order to sell more hardware, not one that competes with other storage providers or aims to record significant revenue from iCloud.

Jan Dawson, chief analyst at Jackdaw Research, stuck with that today. "It's still about selling devices, not selling services," he said. "That said, the increasing numbers of [Apple] device owners means increasing revenue from services."

Apple sold a record 74.5 million iPhones in the fourth quarter of 2014, 21.4 million iPads and 5.5 million Macs.

Dawson declined to estimate how much Apple books from iCloud. He pointed out that Apple does not reveal a number, but also loads a "services" category with such a wide range of revenue streams -- everything from royalty revenue from accessories makers to Apple Pay -- that it's impossible to parse the individual contributions.

One hint of how much content Apple plans to store on iCloud was revealed this week, when the company announced that it would spend $2 billion over 30 years turning the failed sapphire production plant in Mesa, Ariz. into a data center. Construction on the data center conversion is to start next year.