In edit mode, the length of macros are truncated, which means that if you have pages with long names included on the page you're editing, you cannot see the full names of these included pages. This is very problematic if the titles of these long-named inclusion pages only differ towards the end of their titles.
Finding out the full name of an included page now requires manual intervention. In Confluence 3.5, you could simply glance at it in Wiki Markup.
To work around this visual limitation, I've had to rename all the inclusion pages so I can see them at a glance (to work out whether or not they need revising).
Incidentally, expecting a Confluence 4.0 user to simply view the storage format (i.e. XHTML) to see these page names is not an acceptable workaround - especially if you're not going to provide them with a way to edit this XHTML content (in an indented readable format).
Extend the length of the macro (displayed in edit mode) to the full width of the edit box.