I think it's the imaginary pecking order that people get russled about.
I for one feel that Tau are the most deserving of an update, if anything it's to bring in a shooting-emphasized army into 6th edition and update the codex that's at the very front of the "older than you." que.
Daemons were inline with a rules-update but not so soon over others.
"Ambition is the biggest killer of Momentum"
Starting afresh with my Chaos Space Marines.
Project Log Link (Placeholder) -
Project Rebuild, Reboot, Recycle:
Stripping, rebuilding and remaking my Guard army.