I'm not sure that I even fathon the concept of building a modern pc without a DVD drive. There's plenty of DVD movies that have additional PC content as part of their 'added value specials', several gaming magazines have DVD issues with extra content and with the rising number of disks involved in games, the coming switch has been as inevitable as the switch from floppy drives was.
Heck, it was more expensive for me to build in a Zip drive for out-dated compatability with other systems than it was to install a DVD drive, and I have 4 available slots (1 DVD, 1 CD-RW, 1 Audigy Platinum Livedrive and 1 HD cooler for my SCSI drive). I'll be throwing out the DVD in favour of a DVD+R soon.
Honestly, not anticipating this move given the costs involved seems just to be backward.