I like the use of the gnu's horns turned sideways as an 'E'.  It has a fairly clear interpretation yet still has a subtle connection to the gnus logo.  The Swiss army knife, kitchen sink, and gnu icons always leave me grasping for meaning and/or even recognizing what the icon is.

A couple of comments related to Tango have been made, so I'll add a comment on that.

The Tango style guidelines (http://tango-project.org/Tango_Icon_Theme_Guidelines) say

• All Tango icons are stroked with a thin outline
• Use glossy reflection only on objects that have a reflective surface in real life

Stroking the 'E' and reducing the gloss would bring the icons more in line with Tango.

Best,

Kevin Wright