The interview consisted of relatively basic questions around programming in general, and some specific to the job's required programming languages. I think the average programmer should be able to answer those without any prior preparation.
While I was able to answer the former, I lacked knowledge in the position specifics, so I didn't get the offer -- I was informed of that by the interviewer on the spot, in a very polite way and with a very logical explanation, which I greatly appreciated on his behalf.
Definitely one of the best interview experiences I've had.