The new 3.0 iPhone OS is a very nice upgrade, well worth the $10 for iPod touch users. It has updated push capabilities, enabling apps to display notofications on your iPod. I have found that this feature is very nice. I really like the new feel of the 3.0 OS, it's landscape email & notes makes it much more bearable to type on the iPod. The updated tilting sensitivity is also nice for some of the apps that require you to tilt your device. Video recording and editing has been added for iPhones only, video has surprisingly good quality for a cell phone, and editing couldn't be any easier. Voice memos have also been added for both iPod & iPhone, but is somewhat useless for the older iPods since thier headphones don't have mics built in, if you want a mic headset for voice memos it will cost you another $25, slightly annoying, but useful nonetheless. Spotlight search has also been added as well, spotlight is useful because it allows you to search your entire ipod/iphone. You can search for apps, notes, emails, songs, videos, and other. Apple has also enabled bluetooth in all iPod touches, cool but slightly annoying as well because that means that iPods were bluetooth capable the entire time but we just had to pay more to activate it.
These are just some of the many features that Apple has included, along with many bug fixes.
Pros - Landscape email & notes, updated tilt, better push notifications, Bluetooth, video recording/editing (iPhone only), voice memos, updated music player, spotlight search, compass (iPhone only), MMS (iPhone only), wireless syncing
Cons - can't doubletap the home button and have the iPod turn on with volume controls