Google Spaces is the newest Google service to be shut down7
Starting March 3, Google Spaces will be read-only - users will no longer be able to create spaces, share info, comment, or send invites to other people. The service will be killed off for good on April 17. Until then, if you are using Spaces, you'll have plenty time to save any content that you don't want to lose.
In the grand scheme of things, the fact that Google is discontinuing Spaces doesn't mean much. The Mountain View company is well known for developing various services and apps, only to kill them off after a while. Truth is, Google has plenty of resources to experiment with pretty much anything and see what works and what doesn't. As it turns out, Google Spaces is an idea that does not work - or at least not as Google hoped it would. Nevertheless, Google says it'll be using what it learned from Spaces "to improve other products and services." That's still something, right?
source: Google Spaces via Droid-life