This is just a modified version of the Ubuntu Software Center icon for Debian. The reason I chose to make this is that the Ubuntu Software Center recently hit Debian and the current artwork was using the Ubuntu logo. All I did was change the Ubuntu logo with the Debian swirl. To use this, unzip the tarball, then:
cp deb_softwarecenter24.png /usr/share/icons/hicolor/24x24/apps/softwarecenter.png
cp deb_softwarecenter.svg /usr/share/icons/hicolor/scalable/apps/softwarecenter.svg
And so on for the 16, 22, 32, 48, 64,and 128 sizes.
Let me know if you need any help.