This isn't exactly news per se, since we knew that some cleaves were in for a change, but now we know more about the precise implementation, thanks to Tigole:
The following changes to cleave have been made for the 2.1.0 patch.
--Cleaves will only hit people in front of the creature.
--Cleaves will have a chain length equal to the combat reach of the creature.
We still don't have an exact estimate on when this patch will be ready but development is wrapping up and the test phase should begin relatively soon. As a reminder, the patch undergoes internal testing before public, PTR testing.
I'm not really sure what "chain length" means. Does it mean radius, i.e. only people within combat reach of the creature will get hit? If so, I thought that was going on already. At any rate, my Rogue is now somewhat happier in dungeons, although it wouldn't have saved me in Blood Furnace last night (who knew "come here" means "go away or you're going to die in a fire?").
And from the "questions that you never thought of but which are still valid" department, we get an answer to what happens when you put a BoP gem (like the epic ones you can get off Heroic dungeons) in a BoE item, from Aeus:
I just asked a friendly GM to test this: Socketing a BoP gem into a BoE item should not make it soulbound, just VERY expensive ;)
Epic gems are the new designer labels. (<Made by Prada>, anyone? It happened on my realm, anyway.)