>I got the feeling that many inhabitants know little about it, just that "it was, and that is that".

It is quite normal for a city with 1 mln. population to have some number of ass-headed dudes among citizens. But totally your supposition is wrong.

One of the greatest holidays celebrating in Russia every year is Victory Day on May 9 (which is known in the West as Victory Day in Europe, on May 8). Most of 80+ years old living people are WWII veterans and they use to be congratulated this day.
http://en.wikipedia.org/wiki/Victory_Day_(Eastern_Europe)

The Battle for Stalingrad is well described on school lessons especially here in Volgograd. We also celebrate the victory in this Battle on February 2. August 23 is also memorable day as anniversary of Stalingrad bombing. We really remember it and mass media also reminds about it. And plenty of memorials don't let people forget of facts happened in its' position. There are often organized historic pageants of fights with real uniform, guns and even tanks sometimes!
http://www.volgograd.ru/theme/info/vov/100429.pub - fight in Lysaya Gora
http://www.volgograd.ru/theme/info/vov/43634.pub - "Pehotinets" (Infantryman) club of military history

I accustomed that tourists use to visit only Mamayev kurgan and become satisfied. So it's a pleasure for me if people who interested in all significant places besides most popular ones will arrive here!