Is it possible to backup to DVD and restore from DVD without having two DVD drives? Does the image have to be created on another drive, i.e. local drive, and then be split and recorded to DVD?

ShadowProtect can create backup images directly to CD, DVD, or Blu-ray, and you should be able to do it with just one DVD drive.  When it reaches the end of a DVD, it will prompt you to insert another one, so there's no need to split the backup manually.

 What happens if you have to do a restore from the boot CD? Are you able to eject the boot cd after booting and load the DVD's to do the restore?

 I just tried  and it failed. The message "cannot take snapshot. castrophic error". That sounds ominous.

 I just realized 3.1 doesn't support 64 bit Vista. I will update.

You can only eject the CD if you boot to the Recommended Vista-based recovery environment, since it loads everything into a RAM disk instead of running directly off of the CD.  Note:  It does not matter that you may be restoring a Windows XP image (or any other version of Windows), you can still use the Vista-based environment for the restore.