Chris Moschini asked:

> > Why does EM have to be inline and contain inline-only?
> > What's wrong with it containing a DIV, even if it's empty?

Ernest Cline wrote:
 
> [worries about pages of upper case]

A typical contract (including many software licenses) will
contain several paragraphs of upper-case, because the law
says that something needs to be emphasized.

Emphasizing with an <em> is better than just upper-casing,
for the same reasons that <strong> is better than <b>.  (And
for several additional reasons as well, such as readability.)

> [How should default styling work?]

Chris' suggestion of "em" vs "p em" is reasonable.  It isn't perfect,
but it is a reasonable default.  Individual authors can override,
perhaps with a display attribute.

That said, I will agree that many things would be nicer if it were
possible to look at child elements in CSS, just as it would be nice
to restrict descendent elements in XML.

-jJ