imo the nethermap should be done without bedrock, netherrack, slowsand (the huge brown areas on the first map), and all lava.
Maybe also remove the gravel, which will help clean up the 'noise' on the map.
Anyways, some new stuff that was revealed yesterday by Dinnerbone or Jeb:
http://www.minecraftwiki.net/wiki/Block_of_Nether_Quartz Finally a marble-like block! Also, see those vertical striped ones? Marble columns. I hope we get marble block slabs as well.
Tnt dispensers, and mob spawners can be put into minecarts.
Dinnerbone made a cryptic reference to Lead Pigs:
Nathan Adams @Dinnerbone
I tried to run... I couldn't. They were too fast, too many. I could only face the leader and pray to the flying squids.
Whether that was a joke based on the whole 'pig invasion' they were doing to showcase the tnt and dispenser carts or not, we'll see.
There is such a thing called a lead pig and they are lead containers used for storing and/or transporting radioactive materials. I don't see Mojang adding uranium in this update, so.... maybe stronger boars that are part of a herd and get angry when you attack the herd or passively try to push you away if you get too close. We'll know in a few days what that's all about though.