As expected, the Return of the King: Extended Edition is pretty sweet. We watched disc 1 last night. The extended and deleted scenes were great and really helped to add continuity and depth, although at least one moment seemed just a wee bit extreme (two words: skull avalanche!). It also has some easter egg goodness, and it even came with a $5/$10 rebate coupon (depending on the version).
I'm glad Peter Jackson has chosen to make these Extended Editions so cool. The whole trilogy had so much potential to go awry, but the films are great. (Tolkien purists may, of course, disagree.)
I can only hope that the planned Narnia film(s) fare as well.