If you auto sync your iPod, iTunes will replace what's on you iPod with what is currently on your iTunes library, which I assume now is nothing, so it will clear it of everything.
You can get your
music off the iPod by using a 3rd party program (iTunes will only let you backup your purchased music off your iPod) but your photos are stored in your iPod in an "optimized for iPod" state. There
might be a 3rd party program to pull those off as well, but even then, they would only be lo-resolution versions.
Windows XP Pro