A relatively new blog has just come to my attention, with the earliest posts seeming to date from the first of the year: Words Without Borders/كلمات بلا حدود
It concentrates on foreign words that have come into Arabic — not the modern borrowings like television that everybody can figure out, but the older ones. (Everybody knows "Efendi" comes from Turkish, but I didn't know the Greek from which the Turkish was derived: that sort of thing.)
The first several posts are just in Arabic but the recent ones have both Arabic and English explanations. For the language buffs out there.