Here are the new iOS 5.1 (9B176) links from yesterday’s announcement. Note that there’s a new iPad2 model in addition to the new iPad3 models. I’m not sure yet exactly what that model is, and I’m just assuming that the iPad3 sub-models are named the same as the iPad2.
iPod Touch 3G – iPod3,1_5.1_9B176_Restore.ipsw
iPod Touch 4G – iPod4,1_5.1_9B176_Restore.ipsw
iPad 3G/WiFi – iPad1,1_5.1_9B176_Restore.ipsw
iPad 2 WiFi – iPad2,1_5.1_9B176_Restore.ipsw
iPad 2 GSM – iPad2,2_5.1_9B176_Restore.ipsw
iPad 2 CDMA – iPad2,3_5.1_9B176_Restore.ipsw
iPad 2 ??? – iPad2,4_5.1_9B176_Restore.ipsw
iPad 3 WiFi (?) – iPad3,1_5.1_9B176_Restore.ipsw
iPad 3 GSM (?) – iPad3,2_5.1_9B176_Restore.ipsw
iPad 3 CDMA (?) – iPad3,3_5.1_9B176_Restore.ipsw
iPhone 3GS – iPhone2,1_5.1_9B176_Restore.ipsw
iPhone 4 – iPhone3,1_5.1_9B176_Restore.ipsw
iPhone 4 CDMA – iPhone3,3_5.1_9B176_Restore.ipsw
iPhone 4S – iPhone4,1_5.1_9B179_Restore.ipsw
The Apple TV (2 and 3) are still on iOS 5.0, but 4.4.3 was the last link I had. Here are the 5.0 (9B179b) links for your convenience.
Apple TV 2G – AppleTV2,1_5.0_9B179b_Restore.ipsw
Apple TV 3 – AppleTV3,1_5.0_9B179b_Restore.ipsw