Initial communication via email shortly after sending my resume, no HR or phone interview, scheduled to meet the tech team right away. Overall, probably the best interview experience I had so far in my life.
First, there are very few standard nonsense HR questions. Don't waste time rehearsing answers to questions like "where do you see yourself in five years?" (sitting in your chair, sipping scotch, why?), "what can you bring to the company in addition to your technical skills?" (I can bring my cat if you let me) or "Why you chose ABC inc?" (because I hope you'll pay me my salary, right?). Leave that stuff for your next interview with yet-another-consulting-firm. Here, it's all technical. Even better, it's not just a "Please rate your experience with SANs on the scale 1 to 10" type of questions (which have always confused me big time, how am I supposed to know? It's eleven!), there are actual quiz questions. So, brush up your knowledge of networks, Active Directory, standard tcp/ip ports, subnetting et al, you'll need it. Not too hardcore though - I expected more of IOS and Linux.
Second, the interview is very informal and quite funny, so is the general atmosphere. People seem to be genuinely interested in what they do. No dress code (yay!) Metro accessible location, quiet DC suburb. Everyone - from the receptionist, to the HR and the tech team are super nice and friendly.
Worth attending, regardless of the outcome, just to get a chance to see Zenimax/Bethesda from the inside (and a must if you like video games, like myself, - something to tell your friends later) and meet these guys. If you're skilled enough and lucky, you'll see your name in the credits of the next TES series game, how cool is that?