I really dislike when the media feeders, as reported by TechCrunch say things like "Google is Finally Killing Picasa". The word 'finally' makes it seem like this should have been done some time ago, which is completely wrong in my opinion. And as Anil Sabharwal, Head of Google Photos writes, “So we will take some time in order to do this right and provide you with options and easy ways to access your content,”. You can learn more about this move from the office Google Picasa Blog.
This is a good thing, that Picasa is being retired as the newer Google Photos assures the end user that their photos are safely uploaded to their own Google Account. With Picasa, you had to manually upload these and most people didn't understand the reason for it but this should help.
If you haven't seen the prompt when you open Picasa then you can go and get the desktop app for your computer and your other devices from this link. Considering Google now provides unlimited storage (High Quality), there is no reason not to jump on board. If for no other reason you are providing your computer with free software backup for your photos if nothing else.
For those that want to be sure all of their data is backed up then look no further than Backblaze. Just install and forget about it!