http://www.gsmarena.com/android_443_features_leaked-news-8166.php
Frequent data connection dropout fix
mm-qcamera-daemon crash and optimization fixes
Camera focus in regular and HDR modes fixes
Power Manager display wakelock fix
Multiple Bluetooth fixes
Fix for a random reboot
App shortcuts sometimes got removed from launcher after update
USB debugging security fix
App shortcuts security fix
Wi-Fi auto-connect fix
Other camera fixes
MMS, Email/Exchange, Calendar, People/Dialer/Contacts, DSP, IPv6, VPN fixes
Stuck in activation screen fix
Missed call LED fix
Subtitle fixes
Data usage graph fix
Internet telephony fix
FCC compliance fix
Miscellaneous fixes