1) Minor changes in the form of buildings and loot.
2) Added more difficulty:
Every 10 zombies is endowed with custom intelligence.
And other changes in level.dat =)
3) Multiplayer is now available. (for the second player has its own islands)
4) Removed the greeting.
5) Added end.
6) Added tables.
7)Now you can't get to nether using vanilla portal.