http://mojang.com/2012/02/03/minecraft-snapshot-12w05b/
Please delete this if I’m late. 
WARNING: Project City Build CAN NOT BE PLAYED due to this .jar file updating you PAST the server’s version!!!
Derp… didn’t think of the warning when I first posted this. 
What is this about? Please delete?
I think he means, if people already know about this, and it is old news then to delete it.
Yeah. It’s just a weekly snapshot Mojang puts out.
Yeah, I was saying if somone already posted the link.
It was made today, so I know I’m not spreading old news, but I figured I’m not the fastest to share stuff.
Ah, so this is some early release, not an update I need to add to my 1.1 game. I’m sticking vanilla for the moment.