Jeb mentioned on Reddit that some new changes are coming to double doors in the Minecraft 1.2 update. Because of the way they currently work, the Minecraft game build is trying to cram 5 bits of data into 4 bits of data. The new update will fix these problems, but because there’s not really a way to add more data into the older versions of Minecraft, you might have to rebuild every double door setup you have in Minecraft once you update to the latest version of Minecraft.
Other updates that are sure to be lots of fun are improvements to the Creeper AI so that it can better navigate through terrain. Having an Ocelot as a pet will cause a Creeper to flee and stay away from you, so that’s a helpful way of trying to craft or build structures without having to randomly come across a Creeper and get blown to smithereens.
Villagers also will have the ability to open and close doors, and they are supposed to stay closer to their own houses now, instead of spawning in a village and then wandering aimlessly to the ends of the Overworld. The inclusion of villagers opening and closing doors is supposed to make the towns feel much more engaging and busy now, but we’ll have to wait and see when the update comes out ourselves.