Launched in 2006 as an online extension of the Picasa photo management application, Picasa Web Albums didn't become very popular, as Flickr continued to grow. Besides lacking a community of photography enthusiasts and leaving out a lot of basic features like stats or adding a photo to favorites, Picasa Web Albums is not a great name and many might not even know that Google has a photo sharing service.
There are many references in Picasa Web's code which show that the service will change its name to Google Photos. The navigation bar already uses "Photos" as an anchor text, there's a Google Photos Screensaver and the service's blog is titled Google Photos Blog.
Other upcoming features referenced in the code include content licensing options, uploading photos by email and tagging people in your photos.