Q: I recently purchased a Macbook. My iPod classic and iPhone have all previously been formatted to a Windows PC. They seem to be running fine on the Mac, but do I need to reformat them to Mac? If so how do I go about this?
– Adam

A: iPhone and iPod touch devices no longer use a operating system specific format as they rely on a completely different synchronization protocol than traditional iPod models. Therefore, you don’t really need to worry about your iPhone in this case, it should continue working without any issues.
The iPod classic, on the other hand, would be formatted for Windows at this point. This normally works fine as the Mac OS can read and write to Windows-formatted iPods. However, this configuration isn’t officially supported by Apple, and there have been minor issues in the past with using Windows-formatted iPods on a Mac, such as missing or incorrect album artwork on the device. The other limitation is that a Mac cannot be used to update the firmware on a Windows-formatted iPod, so you would need to find a Windows computer in the event that a new software update came out for your iPod classic.
If everything is working fine, you may decide to leave well enough alone unless you start encountering odd behaviour. Should you decide to change over to a Mac format for your iPod classic, you will need to reformat the iPod, erasing everything on it in the process. This isn’t a huge undertaking if you’re using automatic sync and already have everything in your iTunes library, as you can just reload it from there. If, however, you’ve been managing your iPod manually and don’t have the same content in your iTunes library, you will need to first copy all of the content from your iPod back to your computer and reimport it into iTunes first.