Facebook is rolling out a flurry of changes and some of them relate to privacy. From what I read at AllThingsFacebook it's not hitting all users at once so I don't know how many of you have already had a chance to explore. So far, my own clicking around hasn't revealed anything that reduces your level of privacy. In fact, some changes could make it more secure for you, depending on your current settings.
The most notable new feature is that when you update your status, you will see a drop down menu just to the left of the "Post" button.
This allows you to choose between Friends (only your friends can see it), Public (this used to be Everyone) and Custom. If you've created groups, then Custom allows you to send the status only to the specific users you choose. Whichever audience you select, it will be the new default setting until you change it. Also, Facebook says that any changes to your security settings automatically update with your mobile app.
If you're the type of person who wants their profile to be on lock down, choose Friends or take the extra step of setting up groups. If you're not sure what your settings are or want to do a quick double-check, The 10 Facebook Privacy Settings You Need to Know is a great resource to walk you through it. (Caveat: Posted in February, so it may not be up to date.)