I just tried the new 1.11.1 snapshot, and in the list on the Mojang website I noticed this paragraph:
"There is also a new (potentially controversial) change to the combat mechanics. Without revealing what it is, you will most definitely notice the difference when you try out the snapshot. We anticipate much feedback."
I tried the snapshot and started fighting creepers with a diamond sword and didn't notice anything. Is this something that will only be in PvP? I just hope they haven't made the combat more tedious and frustrating than it already is.