I’m a bit late to have stumbled across this information, but it would appear that the final novel in the Harry Potter series will not be coming to the iTunes Store:
You may have the seen the avalanche of press coverage about the new “Harry Potter and the Deathly Hallows” hardcover selling 8.3 million U.S. copies in its first 24 hours of release. […] More than 225,000 audiobook cassette or compact disc copies were [also] sold the first weekend. Those were the best two-day results in audiobook history, according to Random House. […] What’s not available is an iTunes download for your iPod. The first six Potter books are available through iTunes at prices ranging from $33 to $50. But a Random House spokeswoman said no iTunes date has been announced for “Deathly Hallows” and that she has no other information about download plans.
So if you’re still waiting, I suggest running out to Costco and getting the CD version, which had the lowest price I’ve seen by $10, and then buying a copy of Audiobook Builder to make importing it into iTunes more pleasurable. The two together will still cost less than Deathly Hallows would have cost through the iTunes Store, and you’ll be able to use Audiobook Builder on other books in the future.