I received an answer today from Amazon on my inquiry on whether you will be able to buy Kindle books that are on Wish Lists. A standard reply letter on a question they probably get all the time.
Here it is:
Hello,
The purchase and download of digital content from Amazon.com, including content from the Kindle Store, is associated with the Amazon.com account used to make the original purchase. As a result, digital products cannot be given as gifts or added to a Wish List. I am sorry if this information is disappointing to you.
Thank you though for letting us know your interesting in gifting kindle content.
Strong customer feedback like yours helps us continue to improve the service we provide, and we're glad you took time to write to us. I'll send your comments to the Kindle team.
I hope this helps. Thanks for your interest in Kindle!