"World War Z" director Marc Forster recently spoke to Movies.com about the original and ultimately scrapped Russia-set third act of the film. In the process he revealed a few frames of that discarded 30-40 minutes did make the final film:
"So it’s in Russia, at night, in a snowstorm with thousands of zombies and big battles; kind of the scope of the Israel sequence. Some of that footage is still in the film, you see it during the montage when Gerry journeys back to his family on that small boat, we see a few glimpses from that battle."
He also says we likely won't ever see it as a special feature on some future disc release as it remains unfinished:
"I don’t think you’ll ever see the Russia sequence, because we never really finished it; we never spent the money to do the visual effects. Once we shot it and we did a rough cut, everyone agreed that this is too big and too exhausting, it would be better to go a simpler route.
So to finish the sequence aside from fine tuning it you would have to do massive amounts of CG work, which would be in the millions of dollars, so I don’t think anyone would want to spend the money on that. It’s a fantastic sequence, like the Israel one, but it’s just too much. It was too big and not the right ending."