Content type has nothing to do with style sheet information. There's a clear
relationship between the utility of a file and its format. From the point of
view of the author, content type may well be a property of the link -- "jump
to the contents of a file of such-and-such a format". Mmore precisely, it is
a property of the document's representation of the client's request to the
server. So under certain circumstances it may be appropriate to encode the
content type in the document.
As I pointed out earlier, Dan's idea does have one drawback by not
accomodating multiple formats - and I do wish someone would explain in 25
words or less how an html author provides input into how http "negotiates"
with clients about content type -- but a content type attribute clearly
beats hardwiring content type based on file extension. For one thing, an
attribute is easier to parse than a URL/filename.
-kmc