My battery life has been really bad! I was charging every 3-4 days with average use on my 12" rMB but now it's at least every 1-2 days. I maybe average 1-2 hours of use on it per day. I mostly pull it our for quick google look-ups and remoting using RDP or LogMeIn Technician into customer's computers and servers. Also, it seems like it uses battery while asleep, which it never did before. I may go back to turning it off instead of sleeping it until this is fixed. I don't have any rogue processes running that I can see.
As another poster mentioned, I have noticed the slow shutdowns and startups--though it is not all the time; sometimes it's very fast. Also, I have had several out-right freezes that have required hard shut-downs. But this is Beta Build DP1 so I am not that worried about it. I just have to keep my power adapter more handy and actually carry it in my bag for the moment. I haven't tried the permissions check as someone suggested, so I will try that now.