Apple has seeded registered iPhone developers with a second beta of the 3.1 firmware. The first 3.1 firmware beta added
a number of new features to the iPhone's operating system including non-destructive video edits, Voice Control over Bluetooth and a number of other minor improvements.
Release documentation show no major changes for this second beta version, but more information typically comes out as people have time to try it out. We don't know when to expect the final iPhone 3.1 firmware for consumers.