The shorter a URL, the easier it is to share and remember. The downside is, you often can’t tell what website you’re going to be redirected to. We’ll only use g.co to send you to webpages that are owned by Google, and only we can create g.co shortcuts. That means you can visit a g.co shortcut confident you will always end up at a page for a Google product or service.
There’s no need to fret about the fate of goo.gl; we like it as much as you do, and nothing is changing on that front. It will continue to be our public URL shortener that anybody can use to shorten URLs across the web
Blog Link: http://googleblog.blogspot.com/2011/07/gco-official-url-shortcut-for-google.html
Originally posted by Gary Briggs, VP Consumer Marketing