Q: is there anyway to unroot the device after rooting it?
A: Not an automated way (maybe something for v1.2) but it is certainly possible to unroot manually.
Fire up an ADB shell, remount system read/write (usually just "mount -o rw,remount /system", but far from all devices have this exact syntax... ask your favorite dev/chef in your device's forum), delete "/system/bin/su" and "/system/app/Superuser.apk", wipe dalvik cache, reboot, root is gone.