The Mac OS X 10.10.2 update fixes the Thunderstrike exploit, among other security bugs. (Good luck if you have a Thunderbolt-equipped Mac but aren’t running Yosemite.)
It claims to fix Wi-Fi issues, but Macworld and MacRumors both report that Wi-Fi problems persist.
It does fix the nasty Core Data relationships data loss bug, though this is not yet fixed in iOS.
Launchpad’s sparkle for new applications has been removed.
Lloyd Chambers is still seeing problems with dual displays. I’m still seeing problems with the login screen, Mail, etc.
Update (2015-02-03): Edward Marczak:
To call [Thunderstrike], “fixed,” is absolute fantasy. A good chunk of the boot process would need to change to fix this.