This comes nearly on the 6th Earth year on Mars. Spirit bounced down in Gusev Crater back on January 24, 2004. That seems like a LONG time ago!
There was some talk recently about if the rover could use it's arm to pull itself out. Nope, can't work. The arm is way too weak. Kind of like that skinny kid in school that could never climb the rope (uh...that was me).
(see the rover squirm in the photo)