From what I've been told... 2ND GENERATION ZUNES DO NOT SUPPORT AN EQ.
The EQ is handled by a separate chip in the device itself, so this basically means it would be impossible to add an EQ to the Zune 4, 8, or 80. In an interview I listened to, it was apparently to conserve battery life, I'm not sure if I believe this, as you could just turn the equalizer off, but oh well.
In other words, if this is true, which it seems to be... 30gig Zunes only have the EQ after the firmware update because they are physically capable of it, so this petition is kind of worthless.