When you stare at endermen in the any of the 1.8 snapshots and now in 1.8 itself, instead of stopping, staring, and then attacking you only when you look away, they immediately charge at you. I have also seen this in versions lower than 1.8 snapshots, such as 1.7.10, but instead of it always happening it only happened very rarely.
What I expected to happen was....
When looking at a enderman It would wait until I looked away to attack.

What actually happened was...:
The enderman attacked me right when I looked at it instead of waiting for me to look away.
Steps to Reproduce:
1. In a 1.8 snapshot, spawn a enderman and stare at it to anger it.
2. The enderman will charge at you instead of starring back at you.