iOS 4.3.1 is now available.

Apple releases iOS 4.3.1 for iPhone 4 GSM, iPhone 3GS, iPod touch 3rd & 4th generation, iPad and iPad 2. The update is said to include the fix for 2011 Pwn2Own Safari bug and some others. iPhone 4 for Verizon/CDMA is still on iOS 4.2.6.