there are several team "working" together to released Jailbreaks, mindly the iPhone Dev Team and Chronic Dev Team, now in this case, an Original Member of the iPhone Dev team Geohot (which is a little cry baby, and love attention), just released another JB stealing some code from the Chronic Dev team and messing all things up.
Many reports say that the JB works great, many reports that it's broken, specially 3GS new bootrom users, other have report WIfi broken and Buetooth acting funny.
If you decided to use it, be cautions. Greenpoi0n from the Chronic Dev team property test and package will be delay and release sometime this week.