Make a couple of phone calls.
iDVD is a “Must Have". (Yes, it should be included.)
Call Apple they will sent out iDVD at no charge.
800-692-7753
800-275-2273
If you are still within your 15 day return period, nicely explain that you may return the computer without iDVD. That usually does the trick.
Most people report that by asking here: http://www.apple.com/feedback/idvd.html
or here: http://www.apple.com/contact/
they got a free copy of iDVD.
If that doesn't work you can purchase iLife 11 (includes iDVD) on disk (don't get the download) for about $39.
http://www.amazon.com/Apple-MC623Z-A-iLife-VERSION/dp/B003XKRZES/ref=sr_1_1?ie=U TF8&qid=1323229350&sr=8-1