It adds some more fun stuff to use.
some examples...
Propcore(manipulation and spawning of stuff with e2)
ShootTo(V,N,N,N) for e2(Makes any entity shoot at a given direction/vector)
The link: tsvn:http://svn.dagamers.net/wiremodextras/trunk/
The link is auto-svn, so just paste into browser and it will pop up like any other download.