This article is three years old. I was inspired to look it up because this Purim is the third anniversary of the newest blood libel from the Arab world - that Jews eat the blood of Gentiles in their Purim pastries (hamantaschen). And if it wasn't for MEMRI, we wouldn't know about the medieval bigoted rantings that are commonplace in Arabic media.
There are other Arabic media watchdogs as well, like Palestine Media Watch, and MEMRI now has an entire section devoted to TV shows, but the original MEMRI is invaluable and has already shown many times the differences between the smooth Western face of Arab propaganda and the way many Arabs really think.