1. Introduction of a new group of people, “the Other Others”.
2. Smoke monster revealed to be a sentient vinyl copy of The Button-Down Mind of Bob Newhart.
3. Desmond gets visions of Locke contracting Bell’s Palsy.
4. The remaining female cast of Deadwood show up on the show, as members of a shipwrecked jugband.
5. Two words — hair gel.

1. Everyone (excepting Sawyer) grows a full beard.

2. More structures are uncovered on the island.
Among them:
a) A Denny’s
b) A used car dealership used by the Others to practice infiltrating the castaways’ ranks.
c) A Wrestledome containing the dessicated corpses of Dick The Bruiser and the Von Erich Brothers.

3. The mysterious Other Mikhail not only survives, but appears dressed as Shirley Temple and speaks in a thick Cajun accent.

4. The show sucks twice as much as it did in Season 3, which sucked twice as much as Season 2, which sucked twice as much as Season 1.