A new version of Jailbreak has been released that is compatible with iPhone firmware 1.1.2:
Conceited Software/TouchFree has just released its GUI jailbreak. This is the "final bit" that performs the jailbreak after you run OktoPrep in 1.1.1 and then upgrade to 1.1.2. The Software runs under OS X and Windows, grabs the data off your iPod touch or iPhone, upgrades it with the Jailbreak, installs Installer.app and SSH.app, and reloads it back to your unit. The whole procedure takes about 10 minutes and after, you have a fully updated 1.1.2 jailbroken system.
You will need to downgrade to 1.1.1 if you bought a system with 1.1.2 already installed.