Minecraft 1.2.4 - Update Patch Released

Minecraft 1.2.4

+ Chat history and much better chat editing
+ A few new decoration blocks
+ “Back” and “Quit” buttons to OutOfMemoryScreen
+ Made cats more realistic (read: probably annoying). I hope it’s enough to cancel out any joy you may receive from the previous feature!
+ Added a “minimal” debug menu for testing with. Shift+F3 to hide the graphs.
* Made placing half blocks on existing half blocks (to make a full block) easier
* Limit framerate on menu screens, no longer uses 100% cpu and make my computer melt
* Fixed fatal crash for converted worlds to anvil, when there’s blocks at max height
* Fixed an old bug with signs clearing text while you’re editing them in SMP
* Fixed crash when logging in while there are blocks at maxheight at spawn
* Fixed TNT ghosts in multiplayer
* Fixed storage minecarts dropping enchanted items
* Fixed crashes on invalid server addresses when joining a server
* Fixed entities being uninteractable if they existed at login (Multiplayer)
* Fixed dupe exploit with paintings
* Fixed furnaces and dispensers dropping enchanted items
* Fixed the “flickering” of chat as it vanishes off the screen
* Fixed text rendering over items in the container screens
* Fixed exploit with jungle saplings (turns other saplings into jungle ones)
* Fixed launcher opening minecraft dir if the path contains a space
* Fixed an off-by-one lighting bug
* Fixed block transmuting (turning one block into another via pistons)
* Fixed placing mushrooms in daylight, where they can’t survive
* Fixed redstone lamps dropping powered block items when destroyed while on
* “save-all” (server) now works even when you have toggled “save-off”
* Fixed turning half-blocks into full-blocks while you’re standing on them
* Fixed seed displaying in F3 debug when the seed is unknown (multiplayer)
* Fixed villager texture changing clientside per profession
* Fixed falling off ledge corners while holding shift
* Fixed players falling when reconnecting to servers where they were previously flying 

Official Post about the update here