The new PNG icons are modified from Mark James' Silk icon set 1.3, 
found here: http://www.famfamfam.com/lab/icons/silk/
which is released under the Creative Commons Attribution 2.5 License.

http://creativecommons.org/licenses/by/2.5/

The Icons taken from Silk and modified:

connect.png
disconnect.png
away2.png
hilite2.png

Not modified:

hilite.png (renamed from lightbulb.png)

Created by daelstorm (released under GPL v2)
away.png
online.png
n.png
nicotine+.png
offline.png
birdies.xcf