Okay, I do actually own this product, and I have also been a student of Arabic for some years now. I really would not recommend Rosetta Stone products for non-European languages for several reasons, but I focus on the Arabic here (and I assume the learner is a native English speaker):
-The type of Arabic this teaches you is called Modern Standard Arabic (MSA) or Fusha. This is the "higher register" of Arabic which is used in formal settings by the educated class: the news, academics, some clerics, most literature. Generally, Arabic speakers use a local dialect of Arabic, which is very, very different from this version of the language. For instance: imagine reading a work of Medieval "Middle" English. The language would be mostly quasi-familiar English words, but most of the usage, pronunciation, and grammar would seem tricky, overly complex, or old-fashioned. You would be able to understand some of it, but would miss a bit, too. "The sky is blue" would be like "de heofon ist hewn bleu." MSA is like that to 90% of Arabic speakers: not totally gibberish, but not approachable either. Don't misunderstand me though, all Arabic learners should learn MSA, but know that you won't be speaking it much.
-The reverse is also a problem. You can speak all the MSA you want (from Rosetta Stone or elsewhere) but almost no one will speak it back to you, and some people will literally laugh in your face for speaking that way. None of the living dialects of Arabic are that close to MSA, so even if you memorized every word of Rosetta Stone Arabic, you would not be able to understand almost anyone who didn't go to university.
-To make matters even weirder, Rosetta Stone Arabic included the highly complicated case endings (called Iraab) on all the words. That is to say, there are certain changes to the last vowels of most words in the most formal of formal Arabic literature, like the Qur'an, the Bible, and poetry. These case endings mark what part of speech is being used, so for example "kitaab" is "book," "kitaabun" is "book" if it is the subject of the sentence, "kitaabi" is "book" if it is direct object, "kitaaba" is "book" if it is in a prepositional phrase, etc. It is very complex and NO ONE EVER, EVER SPEAKS THAT WAY, even in MSA. Iraab use is technically correct, but even native speakers get confused by it (and rightly so). Not only does it not reflect any normal Arabic speech, because Rosetta Stone does not explain any grammar directly, I seriously doubt anyone would be able to sort out the meanings of the case endings just from context. This one was a major blunder that is mind-boggling for such an expensive product.
-More on the grammar bit: it is great that Rosetta Stone wants to avoid speaking English, but Arabic grammar is not intuitive for English speakers. Therefore, unless you already have a fair bit of Arabic grammar, you will be completely confused. For example, in Arabic there is a system of root letters that make up most words. The pattern of these roots changes depending on meaning, so if a book is "green" it is "akhdar," but if a car is "green" it is "khadr'." Unless you already know that Arabic has a masculine/feminine gender system, and a root for greeness based on the letters kh-d-r, you would not be able to deduce what was happening (I really, really doubt it anyway.) Arabic has lots of grammar that throws English speakers for a loop and needs to be explained directly and in detail: there are tons of ways to pluralize, a "dual" case between singular and plural, a very different sentence structure, and on and on.
-There is no cultural context provided, which is really strange. Why would I need to know the word for "sandwich" in the formal register of Arabic? Why does it teach how to say someone is "Russian" or "Japanese" and not how to say they are "Jordanian," "Saudi Arabian," or "Moroccan"?
I could only imagine two reasons someone would find Rosetta Stone Arabic useful:
1. If they already spoke some Arabic and wanted a refresher course in the more formal parts of the language, which I guess could happen.
2. They wanted to focus specifically on Arabic literature of some sort and already had some familiarity with Arabic grammar and syntax.
Do not buy this product if:
1. You want to learn Arabic from scratch on your own. You will learn nothing at all, I swear.
2. You are traveling to the Arab world and want some basic speaking skills.
3. You want to learn about Arab culture or the language's use and history.
I didn't intend to rant but this is a very expensive product and it really is not worth the cd its copied on. If you want to learn MSA or one of the many dialects (or better yet, both), get a dictionary, a class, and a plane ticket.