On another 1.4 RC2 installation using the Enhanced Search 1.1.1 add-on the "Matched Users" block on the search results page only appear when you perform the search being logged in as an admin (and maybe as a mod too... haven't tested) but if you're a regular member or a guest then that block will not be displayed.
Unless I'm missing something here (like a usergroup permission) then we may have a bug here...
EDIT: just tested here and noticed that the Matched Users block always appear regardless if you're a member or a guest. And I'm pretty sure that this forum is using the ES add-on. This is a very inconsistent behavior but I'm not sure if this is a bug.