You're not alone - I'm installed Windows (8 Pro 64-bit) on a MacBook Air Mid 2013 yesterday from the OEM/system builder media, and Boot Camp Assistant 5.0.4 didn't recognize the DVD. It asked for an .iso disk image instead, and I created one in a UNIX geek way**, but if you're an average mac user, you'll want to create one using the Disk Utility:
1) Open the Disk Utility. This is in the Utilities folder (go to a finder window and type command-shift-u)
2) Click on your DVD to select it.
3) In the File menu, select New -> Disk Image from "HRM_CCSA_X64FRE_EN-US_DV5"… (or your Windows disk title)
4) In the Save sheet, select Image Format: DVD/CD master. The Disk Utility saves this with the file extension/type .cdr, but this is the same file format as .iso. When the Disk Utility has finished, find the file you save and change the file extension to .iso.
5) Launch Boot Camp Assistant and select the .iso file as the source of your Windows installation.
Since I have a MacBook Air, the windows source was copied by the Boot Camp Assistant to a USB flash drive. MacOS X restarted and Windows was installed automatically, but the Boot Camp driver installer wasn't automatically launched at the end of the Windows install. I opened the flash drive's BootCamp folder and double clicked setup.exe.
Voila! The best trackpad anywhere! Network! Sound! Brightness control from the keyboard! The best Windows 8 computer!
** In Terminal: diskutil list; diskutil unmount /Volumes/HRM_CCSA_X64FRE_EN-US_DV5; sudo dd if=/dev/disk2 of=win8pro.iso. Use the output of 'diskutil list' to match your Windows 8 CD/DVD to a disk# for the 'dd' command. Be very careful.