Mojang is heading off for the winter holidays soon, but before they do, the 1.8.2 pre-release 1 was sent off on its way, right into your hands! This pre-release mainly focuses on fixes, squashing bugs, and some performance enhancements. Among the bugs fixed include mobs following players (as though hostile) in Spectator Mode, explosion force with directional bias, and some revisions to explosion physics that will, among other things, reduce how far explosions can send objects.
To get pre-releases, open your launcher and press the “New Profile” button. Call it “pre-releases” and check the box saying “Enable experimental development snapshots” and save. To switch to the normal version, you can select it in the dropdown at the bottom left corner of the launcher. Back up your world first or run the game on in a different folder (See the “new profile” dialog). Easy!
Cross-platform server jar: https://s3.amazonaws.com/Minecraft.Download/versions/1.8.2-pre1/minecraft_server.1.8.2-pre1.jar
Report bugs here: Minecraft issue tracker