The Safari Reader
I am impressed with Apple's most recent upgrade to Safari with Reader, so much so that I am using Safari sometimes. When you are looking at an article, but don't want to deal with strange formatting and brand material and ads, you can simply click the Reader button, and you are given a nice clean page that you can read.
Great feature. But it made me worry that perhaps people will want to do this on my blog. People like me. So, ahem, new layout.