Ok, since everyone here is posting gibberish, I actually downloaded the latest beta 6 and here are my results...
#1 If you have more than 1 display, Yosemite is DOA for you. Yosemite will never remember your startup display leaving you scrambling for a 2nd display not turned on or an HDTV remote. I've reported this since Beta 1. Apple has chosen not to fix the bug. This does not happen in Mavericks btw with the exact same displays or even in Leopard. I have tried everything from plugging in/out both displays, zapping PRAM. YOSEMITE IS JUST DOA on THIS and you should probably wait for an update before upgrading if you have a 2nd display.
#2 It's unclear to met yet whether the Bluetooth/iPhone thing is fixed or not so far.
I'll post more this week to see what happens, but #1 definitely makes YOSEMITE DOA for me. Just too much of a pain and hoop to jump through on every reboot. Nobody with Mavericks will like this problem. I got into the beta program to help fix things. If Apple doesn't fix this, I will delete Yosemite and stick with Mavericks until they figure it out. Lots of people have multiple displays today. This is totally unacceptable.
-- Mac Pro 2.93 GHz Quad Core, ATI HD5770, 12 Gb RAM, plenty of Tbs HD space.