This term has not yet been assimilated into English. If it were English, this would be an acceptable way to say it. The pronunciation recorded below by Prolagus is indigenous. --(chelster, see pronunciations)
P.S. I miss skipvia (aka magnificent bastard). Good thing he's still around on Facebook. And Frindley, too. Where have all the Frindleys gone... long time passing... where have all the Frindleys gone... long time ago?
Just to reassure Pro, and let everyone else know: This summer I had the good fortune to be in Sardinia (Calasetta, specifically), and we happened upon a streetside sausage vendor who was very generous with samples, despite the language barrier. (His English was as absent as my Italian and Sardi.) Then I noticed the handwritten sign: Casu marzu. I couldn't remember why that was so familiar. I said it as best I could. The vendor lit up. "Casu marzu tradicional, he said enthusiastically.
Lifting the corner of a canvas covering at one end of his table, he sliced off a bit of cheese for my companion. It was delicious. Another sample came: Creamier, and apparently heavenly in flavor, unlike any other cheese: Smoky, salty, tangy. Remarkably delicious -- quite possibly the best cheese ever tasted. Not long after, of course, Wikipedia reminded me that I had first learned of this delicacy right here on Wordnik (neé Wordie). And hey, no enteric myiasis yet! Or any other ill effects that we can identify, for that matter.
They are speaking Italian, with a strong Southern Sardinian accent and a few words coming from that dialect of Sardinian language. For example: at 1'00'' they say "A me lo date un passaggio?" (Sardinian-influenced Italian, "can I get a lift?" At 3'30'' they speak Italian. Song at 4'22'' is obviously Italian. 4'45'' sounds mixed, although I can't really understand what they're saying.
They actually say something else before that, perhaps "Wait!"... I have a feeling they wanted to wait so that they could eat together, and he just bit the casu marzu on carasau (yes, the bread they spread it on is carasau).
...Then laugh out loud. At 5'15'', after the correspondent talks to the little girl in English (she can not understand him, since we do not learn English so early), they tell him "Vai, calloni!". Calloni is a Southern Sardinian (Campidanese) word meaning "sucker", "gull" (coglione in Italian, where it has a more aggressive connotation).
EDIT: I don't usually like such behaviors, but "calloni" is not really that offensive. They would have probably said it in English if they knew the word.
"Risk of enteric myiasis: intestinal larval infection. Piophila casei larvae can pass through the stomach alive (human stomach acids do not usually kill them) and take up residency for some period of time in the intestines, where they can cause serious lesions as they attempt to bore through the intestinal walls. Symptoms include nausea, vomiting, abdominal pain, and bloody diarrhea."
A food - an I use the term loosely - that definitely qualifies for my Yuck list.
I think you'll have to ask sionnach what it is. I was remarking on a link to Wikipedia that someone else posted--I thought it was here, but apparently not--to casu marzu. I'd go find it and post it here but... it's too gross, so look it up if you want to know. :)
Edit: EEEW. I went and found the link. Have fun (not).