Sure, Apple’s iPhone OS 3.1 includes a couple of new goodies like MMS and iTunes-based App management, but if you like your Jailbroken or Unlocked iPhone, sit tight until Dev-Team gives the all clear. You could otherwise lose your unlock for good.
If you want to jailbreak your new iPhone 3GS, iPhone 3G, iPhone 2G, and iPod touch 2G, now can get RedSn0w 0.8, and do it easily.