George Hotz or geohot the developer of jailbreaking and unlocking tools like blackra1n and blacksn0w has tweeted that “There is no solution for 3.1.3 on newer devices or 05.12.01 There is no untethered jailbreak. I don’t know if/when these things will exist.” This clearly means that Geohot will not be working on his tools to support 3.1.3 jailbreak and unlock. Moreover as many are expecting a bigger news from Apple regrading new version of iPhone and iPod Touch along with new iPhone OS, it might not add much value to start working on 3.1.3 firmware.
http://www.techhail.com/iphone/no-jailbreak-with-blackra1n-for-3-1-3-iphones-on-05-12-01-baseband/3205If you guys have updates, please post a shoutout! thanks!