Yeah it is.
I managed to enter The End world and the Enderdragon is FUCKING AMAZING! Its a boss fight.
You have to shoot all of these Ender Crystals ontop of the Obsidian Towers because the Dragon uses them to heal himself, after that you start to kill him. I've done it on Creative Mode but its defently possible to do on Survival.
After you kill the Enderdragon, It drops so many EXP Orbs, a portal appears, and ontop of it is a Dragon Egg, its meant to be very important but I don't think it has a current use. When you enter the Portal, The ending credits and a really complex, confusing poem about you as a player and the Minecraft world scrolls across the screen, After they you leave The End and spawn back at your Spawn point in the Overworld.
Pretty awesome stuff, I guess we know why its called The End
http://www.minecraftwiki.net/wiki/Enderdragon_Egg