I finally figured it out. Way down at the bottom of the downloads page it says:
TurboTax products ordered on a CD won’t show as an available download in the above list. If you ordered a CD but want to access TurboTax as a download instead, enter your license code here – you’ll find your license code in the instructions that came with the CD.
The license code was also available at the top of the list and in an e-mail that I was sent, even though I never got the CD. I was able to download the software, but if I hadn't paged all the way down to the bottom, I would never have seen how to do it.
