This is yet another case of confusing a constant with a final (YACOCAFWAC? - that sounds bad now, doesn't it?). It is a constant, that's why it compiles. It is a final, by consequence. Seems like these SCJP books provide more confusion than anything.
I'm hangin' around here because I'm waiting for 310-055 (no, not the beta) - any news yet? Cripes, it was "Spring 2005" last I checked, and that was for the northern hemisphere. It's getting pretty dang cold around here. Slipped the deadline, sure, happens all the time... but when can we expect an exam release?