iOS 4.2 on iPod Touch 2d Gen : is it worth it?
I'd say yes. I just upgraded a pair of 2nd gen iPod Touches to iOS 4.2 and it's been really solid so far - it hasn't slowed down the device or impacted the battery as far as I can tell. If you have an Airport Express or new Apple TV the AirPlay feature is very nice - this Thanksgiving I really enjoyed being able to stream music to a pair of speakers directly from the iPod in my pocket. (this will affect your battery as the device has to keep WiFi active to stream)