This makes it very easy to share with other people, but there are a few new features you should be aware of. First, if you want to change your visibility settings, click the "Get sharable link" at the top-right corner of the window (see below). This will allow you to change the Global access settings of your document.
If you want to see the old format of sharing with People, click the Advanced link in the bottom-right corner of the page (see above). It will open the page to the more traditional sharing window.
I think this streamlined share window will become very easy to use. As with most Google changes, it is different and will take some getting used to. I hope I get used to it quickly.