Just out of curiosity, I looked at the HN RSS feed and they still use regular escape for titles (and some other things, except description). It means they use 2 versions of escape instead of 1. So why not just use 1?
The description contains HTML markup, such as <p></p> for paragraph breaks. CDATA is a nice and clean way to encode them without breaking anything.
The title doesn't contain any markup, and shouldn't. A good old escape function covers both the "doesn't" part and the "shouldn't" part.