Q: I want to replace my second-generation iPod touch with the new fourth-generation iPod touch. Seeing that iTunes backs up the settings, can I port all my settings, apps, etc to this new iPod and make it just like my old 2G iPod?
A: Absolutely. You’ll simply want to make sure that you plug in the old iPod touch and let it back up its settings before you plug in the new iPod touch for the first time. You can confirm that you have a current backup of your old iPod touch by going into your iTunes Preferences and checking the Devices tab, which will list all of your iOS device backups and the date and time of the last backup.
When you connect your new iPod touch for the first time, iTunes will ask you whether you want to set it up as a new iPod touch or restore from a backup. Simply choose the backup from your second-generation iPod touch and iTunes will apply this to your new device, including all of your synchronization settings, after which it will begin syncing the same music, apps, and other media content as you had selected for your old iPod touch.
Note that if you’ve already set up your new iPod touch as a new device, you can still restore this old backup by right-clicking on it in the Devices listing in iTunes and choosing the Restore from Backup option. iTunes maintains separate backups for each device, so your new fourth-generation iPod touch will not overwrite the backup from your original second-generation device.