Yes, it does. Not shitty, its called improvement. You should run build 556 until you know your plugins are updated to run on the latest builds.
That is what happens when you stick to the cutting edge. That commit was made three hours ago, you expect all the plugin authors to have caught up already?
If you aren't developing plugins, you probably don't need the cutting edge CraftBukkit. Is there a particular reason you wanted a more recent version than 556?
servers run much faster when you have to disable all your plugins because they are not compatible with the build from 5 minutes ago