We can change the style of the @id@ markup, it's orthogonal to the
hyperlinking issue. I personally like the style use in

http://code.google.com/appengine/docs/python/datastore/modelclass.html

where identifier are monospace but appear in a color that makes them
stand out a little bit more.

I found on that page, because the green monospaced font makes certain identifiers stand out within the middle of a line of ordinary black text, I expected them to be hyperlinked, and was surprised that they are not. Indeed, the highlighted identifiers (type names, attribute names, etc), would be exactly the kind of thing I would want to lookup in order to fully understand the documentation.