Well.. OFCOURSE it's not a novelty if you're living in the states, Korea or Japan but it is in Belgium. I've seen this evolution take form via reports on internet, where i'm already dwelling for 17 years. The first time of "unusual store events for games" were on sites like N64, (later to become IGN) where you could read (and see images) about people forming endless lines in front of the stores before opening time, at the launch of the Nintendo 64 console. Ofcourse this wasn't a "night launch" but it was still something that you wouldn't at all see here in Belgium for a long time.
Only after 2005, we began to see signs that Belgian fans could be exsentric enough to camp in front of stores or to form big hordes for a game's launch. And when VTM News started reporting about nightly call of duty launches - and this would only be at the lauch of modern warfare 2, because no call of duty game had ever that kind of media attention here - , then the Game launch craze train finally left the station and arrived at our country.
Now back to the d3 nightly launch. It's still very new that this kind of thing happens and what's even more special about it is that a "supermarket" organizing a night launch event of a game. If you know the history of how game retailers came to be, how small electronics stores and big supermarket's stock/sale density comparison is, you would be almost think it's an oxymoron
Back in the days, when you went to the supermarket and you visited the "media" department, games were nothing but a sad bucket of gathered species that nobody played. Mediamarkt ofcourse combined 2 elements that were long considerate opposites, specialization and "being a huge store". So in that regard I found it to be quite extraordinary that a company like Media Markt would start to hold events that were for a very specific niche in their market, and so at least in Belgium they struck a deal with activision-blizzard to hold the diablo 3 nightly launch event, including several prize contests. When I arrived to the event, I was told that (Media Markt) Antwerp had aquired the license just in the nick of time to hold an event as well, it wasn't even on the blizzard site where all the events were listed.
It becomes even more crazy that I heard that Media Markt had actually aqcuired the event in favor of our most prominent gaming stores here in Belgium called Game Mania, which previously held all Call of Duty nightsale events.
Next up in this particular store is the launch of black ops 2. It seems to be an activision/blizzard thing to choose Mediamarkt for these things. Ofcoruse they have the volume and space potential to sell much more quantities and I guess it's prefferable over the "boutique" kind of approach that game mania has.
BTW here's a d3 mediamarkt launch impression that I did in may 2012 of the mediamarkt store in Hasselt. It's rather small sized but I'm already amazed at the amount of people showing up. As the denizens of gamers here in Belgum somehow only seem to clutter together on LAN parties and gamer specific fairs. I mean you don't really see a very open mentality of this yet that spreads to mainstream exhibition of "being a gamer".