The first public beta of OS X Yosemite 10.10.3 is out, giving brave users access to Apple’s new Photos application, and a ton of other new features. Betas are always tricky in that they could provide an unstable experience, so I wouldn’t recommend it unless you can handle the instability of unfinished software. But if you do want to brave the unknown, there’s a lot of stuff to look forward to with Apple’s improved software.
We already gave you a glimpse of what Photos for OS X has to offer; it’s basically a replacement for iPhoto, offering the same experience you’d get on mobile, but on the desktop. That means you’ll be able to edit pictures with some really easy tools, and also sync your pictures across devices more seamlessly than before.
The public beta also include stuff like new Emoji, and two-factor login for Google accounts. If you’re a registered beta user, then you should be seeing the option to update soon (build 14D87). If you’re a developer, none of this is new, though the release notes do say that the public beta should improve the stability, compatibility and security of your Mac.