Since they can't avoid hacked iPhones no matter how hard they try, Apple seems to have prepared iTunes 8 to avoid pwning, disabling this ability in mint iPod touch and iPhone devices. But don't fret, because the iPhone Dev Team has already launched a counterattack:
The nice thing about iTunes decisions is that we can provide you with patches to counter them. We have one such patch already for Mac iTunes 8 for iPod touch. We'll be working out the full suite of patches for all the combinations over the next week.
Begun the Apple-Hackers iTunes Wars have. [iPhone Dev Team Blog]