The trouble with Athenaze is that the original version is English and not much like Lingua Latina. However, some brilliant Italians who idolize Hans Orberg's method (and rightly they do) refashioned a new edition in his image. But since it's technically just a foreign language 'edition' of Athenaze I don't think there is any demand to translate it back into English. So we English speakers are left in an awkward situation where the foreign edition is superior (so I'd argue) to the original, but without hope of seeing a translation of it. I haven't done more than flip through the English Athenaze, but it looks more like a grammar that provides numerous reading sections, rather than an intuitive reader w/auxilary grammar.
Forgive my rant. To answer your question, I don't think you'll see an English Orberg Athenaze anytime soon. However, you could
tackle the Italian edition without much more than an Italian dictionary. This would be possible if you will be getting your grammar explanations elsewhere, which seems to be the case.
Look at the image on this page, for example:
Here is the Amazon preview of the English edition (note the lack of pictures, diagrams, marginal glosses etc.):
http://www.amazon.com/gp/reader/0195149 ... eader-link
The only Italian to be found is in occasional, one-word definitions at the bottom of the page. If you look up these words all the rest will be intutive/visual, as demonstrated in the marigins etc. You'd want to look up italian translatiosn in the glossary, too. There is grammar and exercises at the end of each chapter in Italian, but they haven't been anything special so far. The real treasure is in the continuous, graded reading. If you already know a lot of grammar you'll progress quickly.
I heartily recommend this book. Of course, you'll probably have to order it from Italy
I'm flying through volume I, and I'm not looking forward to paying euros/international shipping on volume II.
If you were to need any help, I'd be happy to offer my amateurish translations of all the Italian parts/help in any way.