Well, there's not really that much bugs or glitches that I found since I've only started trying out the 1.8's third pre-release update.
So the first bug/glitch I found when I first loaded a newly created 1.8 world, my player model/skin was alex for about 5 minutes, then it changed to my normal skin.
The second bug/glitch that I found was that mobs were moving "laggy", they were moving as if I was playing in a multiplayer server, and me or the server has a really slow internet
The third bug/glitch is that chunk error happens often more than usual, and the chunk loading speed was really slow.
The fourth is some lighting and particle glitch in the dark.
The fifth one is when I try to load or create a new world, it takes more than a minute.
I guess those were some of the glitches I found in the pre-release, hope you guys could fix some of these stuffs. But thanks for taking a look in my report