all I can think of is bugged Endermen in the snapshot release.
Also note that the windowpanes which are easy to break, have been left alone, if a person were randomly breaking blocks a windowpane would be one of the easiest things to go. Most of the damage has happened to wooden parts of structures.
A possibility could be, that mobs on fire are now able to alight wood and other flammable blocks.
But that doesn't explain the missing anvil.