Gearlog scored an interview with Apple's Greg Joswiak that shines a light on some outstanding questions about the iPhone and iTouch. In a nutshell, the key points are:
No Bluetooth on Touch. Internet pictures implying otherwise are errors.
Touch will run iPhone software. Same hardware as the iPhone, same OS. Software should port without problem.
Apple makes no accommodations for hacking. Software updates will continue to "reset" iPhones and Touches. Apple does not actively oppose 3rd party hacks but they will not support them either.
No SDK. I'm reading between the lines here, but Joswiak's "not hate" and not "support" indicates that Apple has no plans for open 3rd party development.