iH8sn0w has released Sn0wbreeze 2.2 for Windows, which allows users who want to jailbreak and also unlock their iPhone to update their iPhone with a pre-jailbroken iOS 4.2.1 firmware while preserving the baseband from getting upgraded so that it can be unlocked using Ultrasn0w.
Sn0wbreeze 2.2 For Windows: iOS 4.2.1 Untethered Jailbreak For iPhone, iPad & iPod Touch Released; Fixes iBooks Problem
PwnageTool 4.2 For Mac: iOS 4.2.1 Untethered Jailbreak For iPhone, iPad, iPod Touch & Apple TV 2G Released; Fixes iBooks Problem
PwnageTool 4.2 will allow iPhone users to safely restore to a pre-jailbroken iOS 4.2.1 firmware and retain their current baseband so that they can use Ultrasn0w to unlock their GSM iPhone. PwnageTool 4.2 also includes fixes for iBooks issue that we had reported earlier and Wi-Fi problem on Apple TV 2G.
When Chronic Dev Team released Greenpois0n over the weekend, they had listed iPhone 4 Verizon as one of the supported iDevices in the accompanying Readme file.
At that time, we felt it was a little premature to mention it as only one customer had managed to get their hands on the Verizon iPhone.