When I tested Windows 8.1 Preview I had this same issue with the Atheros wireless connection. The same thing is happening with Windows 10 Technical Preview. So I am pasting the solution in case it helps:
I own a Lenovo G470 and my problem is solved.
Device manager was showing I had a Realtek wireless lan driver facing a startup error. I tried updating the driver even with a LAN connection working but had no luck.
Then I downloaded the latest Realtek/Atheros bundle drivers from the Lenovo support site, installed them and still no luck. The driver shown in Device Manager seemed to be the same that was installed before and still not working.
So I tried to update the driver choosing the Browse My Computer for Driver Software / Let me pick a list of device drivers. It showed three options: Realtek driver, Microsoft driver and Atheros driver. Tried each one, as soon as I chose the ATHEROS driver the wireless lan icon appeared and everything started working!
I hope this helps someone.
Now my Windows 8.1 notebook rocks.
Best regards and thanks for the help!