In looking at updated statistics, I found that the all time top 10 worms intercepted in email had changed substantially, as half of these are now Netsky variants.
Message Labs - Top 10 Viruses of ALL TIME
http://www.messagelabs.com/viruseye/threats/default.asp?toptenduration=all
1. W32/MyDoom.A-mm (62M)
2. W32/Sobig.F-mm (35M)
3. W32/Netsky.B-mm (9M)
4. W32/NetSky.D-mm (9M)
5. W32/Klez.H-mm (8M)
6. W32/Swen.A-mm (5M)
7. W32/Netsky.P-mm (4M)
8. W32/Netsky.C-mm (3M)
9. W32/Yaha.E-mm (2M)
10. W32/Dumaru.A-mm (2M)