It depends on what you mean, really. For the most part, the core facts haven't changed much. The overall narrative is roughly the same. In the past forty years, historians have spent a lot of time fleshing out the entire story -- I haven't seen the World at War since I was a kid, so my memory is hazy, but here are a few things that I think you should keep an eye out for:

1. The emphasis on the West as the driver of the European War. In reality, most of the fighting and dying took place in the East, with Russia deserving far more credit than it got during the Cold War for defeating Hitler.

2. In the Pacific, pay attention to how they frame and and narrate the war. Racism played a far larger role (on all sides) than anyone liked to admit 40 years ago.

3. Pay attention to the 'epic battle' narrative that was once used to describe the Eastern Front. Scholarship now is generally moving toward the view that the East was too big to be won or lost in a single battle.

4. Beware of how Nazification is treated. Though most German soldiers weren't die-hard Nazis, the myth that the Wehrmacht was some noble institution fighting for Germany (rather than the Nazis) is fairly false, especially in the East. By the end of the war, the Wehrmacht was one of the strongest bastions of Nazi support.

I can't think of anything else off the top of my head.

A minor point, but it wasn't produced by the BBC. It was made by Thames Television, a commercial TV station based in London.

To add to NervousMcStabbys excellent points.

1. I think the reason Kursk and Stalingrad were viewed as such was because of the epic scale of destruction on both sides. After Kursk, the German army would never launch another general offensive in the east during the war (albeit limited ones here and there.) Which is why it is generally seen as the point in which they (the Germans) had lost the ability to win the war, which of course doesn't mean they had lost the war in the east.
2. I would be weary of some like Donitz, Speer and Wolff. Donitz was a rabid nazi and doesn't get held to task when he is interviewed, not sure if it was common knowledge in the 70s, but it sure is today. Speer is a VERY controversial subject, many believe he is self serving and not genuinely apologetic. Wolff, who was Himmlers adjutant and eventually the ranking SS man in Italy does give an account of Himmler at Minsk which is considered one of the turning points in the decision to start killing Jews in a more humane way (for the killers, imagine that!)
3. All in all, I think its still one of the BEST documentaries out there on world war II. The facts are not off base as NervousMcStabby has correctly pointed out.

I'm not familiar with the work but several big things have changed since 1973:

• The iron curtain went down and historians got much better access to soviet records which has dramatically helped to flesh out that perspective on the war.
• Official secrets acts and such have timed out so the victors are releasing more primary source documents that shed a much more interesting light on things.

So we can get a much more accurate picture from current histories and some things that were speculated at have been confirmed or denied, such as the whole enigma thing as mentioned in this thread.

I came here to say two things. First, that documentary is great (from my perspective as a non-historian viewer). I really appreciate all of the interviews (including one of the last chapters which has a "perspective" view from then-modern historians about the war and included some interviews with Stephen Ambrose sporting a sweet haircut, FWIW, he wrote the book on which they based Band of Brothers and helped found the D-Day Museum, which became the National WWII museum... and which I can see from my office as I type... That museum was great and it's only gotten better... Come to New Orleans!)

Second, I am interested in the eastern front, so, while The World At War does cover the eastern front, it does not do so with the same level of detail. I have read on Reddit in the past that the Russians took objection to this and funded their own counterpart (or add-on) to The World At War, specifically to add more coverage of the eastern front.

Does anyone know where to find the Russian version or what it was called, etc?

adding to the question: Why would our perception change at all unless someone tries to rewrite history (negative) or a mass grave is found (positive)?

One thing to consider, that I haven't had a chance to look at with regards to the title in question, is the footage. In the US documentary Victory at Sea a lot of common footage was used multiple times, and if they didn't have exact footage they used what they considered as close. That's why the "zeros" diving down to attack Pearl Harbor are actually American training planes that were filmed diving as part of an exercise.

I"m not sure if you mean to discuss the visual side of the information as well as the narrated facts.

Did they interview anyone from the USSR for W@W? I don't remember anyone. Molotov and Zhukov were alive at the time.

Where's a good place to watch said documentary?