This piece at Slate about the difficulties of learning Arabic actually is pretty good; at least the article didn't sign up for a course and decide after a month that it was too difficult, and then write a complaining article; he clearly has enough knowledge of the language to write intelligently about it. And an appreciation of the differences between the literary and colloquial languages. I could quibble about a point or two here and there but it's probably a good piece for those thinking about tackling it: a bit cautionary (it isn't Spanish for American learners), but reasonable.
In my younger days I once worked for a while in a bookstore specialized in language learning, and a lot of customers were interested in Arabic. Oh, you know, something with tapes that will get me ready for a business trip; just enough to get around and read a newspaper. Good luck: those are quite distinct tasks, and at least as I was taught it, it took a good part of the first year to master the grammar enough to look words up in the dictionary. (They're listed under the triliteral root, so you need to know the grammar: no simply looking them up alphabetically.) But after decades with the language, I can assure you that it really is possible and, yes, worth the effort. Just remember its not an Indo-European language. The author of the article has a fellow student in his class from Israel and notes, of course, that he has a leg up from the start, since Hebrew has a similar structure.