As ```<link>``` tags are used for many other things (icon, search, alternate, etc) (see http://www.w3.org/TR/html5/links.html#link-type-stylesheet and http://diveintohtml5.info/semantics.html) I think that is a bad idea. In fact I just tested in Safari and if ```rel="stylesheet"``` is missing then it doesn't even load the stylesheet. I think we should do the same.