Device:
BCM4313 802.11b/g/n Wireless LAN Controller (rev 01)
This is the built-in wifi on the Lenovo B570 (and many other laptops).
[UPDATE: As of updates applied on 15.04.12, wifi is again broken (curse you Fedora and your inadequate testing suites!) – I’m currently working on finding a fix ]
[UPDATE: The fix is to connect temporarily using another method (ethernet cable, 3G, or wifi dongle), update your system using yum update, and then reboot.… Read the rest