All I know... I bought my copy of HP7 on July 21st (I live in the Canary Islands... I don't think any
other book has ever been released in English at its worldwide release date). I read it that same saturday.
The book won't be published in Spanish until about next February. However, there are already several translations which can be found in the Net (some of them quite good). I downloaded it and put it in my SPR.
Net result... My girlfriend, who wouldn't touch the Reader with a stick, now thinks it's the
way to read. She is enjoying HP7 months before she was supposed to, and I have also enjoyed the fact that I can talk to her about the book right now
Of course, we will buy the Spanish version as soon as it is released, just to support the author. but e-reading is really much more comfortable.
Since we are buying two copies of the book (one in English and one in Spanish) I don't feel I'm doing anything unethical by downloading the translation, no matter what Ms. Rowling thinks. It's just a matter of convenience.