From the Word of Notch:
"SMP Health Update is out. I’m expecting bugs on this one, so I’m monitoring the usual channels (irc, twitter, email) extra carefully.
Basically everything I talked about in the last post is done, with some extras such as visible hurt animations (how did I forget that?) and visible fire on burning mobs.
The lighting still isn’t right, I need to rewrite it. I think I know what the problem is now, though. Or rather, I know what ONE problem is. You know when you’re traveling by boat, and you see weird strips of light on the ocean floor in multiplayer? That.
Also needed is visible armor on players and mobs (sheep!), and some tweaks to reduce laggy moving mobs. And bows and arrows.
There are a couple of new settings for the server:
pvp. True by default. If this is set to false, players can’t hurt other players.
spawn-monsters. True by default. Set to false to remove all monsters.
spawn-animals. Also true by default. Set to false to remove all animals.
Wow, that broke the game. Hold on while I try to fix stuff.
I’ve uploaded a new server and a new client, fixing the two major bugs I heard about.
I had to disable leaves decaying again (sorry!) because it caused infinite loops in certain situations.
Keep me posted, and I’ll keep fixing!"
I understand that the game is still in its alpha phase, but in all honesty releasing an update which ends up breaking the game and wrecking people's save files is rather irresponsible. Did Notch do any testing at all before releasing the update? Is he becoming lazy, or did the minecraft community pressure him into releasing the update as quickly as possible? Or did he simply screwed up? I don't know. Let's just hope it won't happen again.