Yes I think that some of the archival footage is new. There are clips here and there that I recognize from other shows - audio too. For example, last night they had that clip where the B-17 is going into a nose dive and you hear one of the aviators in the plane filming it saying something like "C'mon you guys, get out of there." That I have definitely seen before (possibly in the "Warplane" series). But there is just tons of stuff that is brand new. All this stuff abut American civilians in the Philippines, and interviews with them, the stuff from the people in Luverne, Mobile, Waterbury and Sacramento, the reporters with the troops in North Africa, Sicily and Italy, etc. A lot of that seems very new to me. They have found lots of people to talk about the war and the wartime which probably haven't really given their stories before - not to a big audience like this - which I think is what Ken Burns is going for... there are endless stories about the War because it affected every person in America (and other countries, but this film is about the American War).
It is true that the contributions of the other countries are not being focused on, but I wouldn't say they are being totally ignored. They skipped over most of the pre-Pearl Harbour stuff. They actually worked their way backward from Pearl Harbour (back to 1939) in part of episode 1. There has been some mention of the Poland, Norway, Denmark, Belgium, France...... (but just barely).... several mentions and some footage of the Russians being hard against it during these first few years (the whole war really, but they haven't gotten that far yet)... the Blitz (some footage), the British in North Africa (mostly focusing on the Americans, but some shots of Brits with Yanks), some footage from Nanking in episode 1, etc. I always like see the Canadians in Hong Kong and Italy remembered. Hopefully we'll at least get a mention for Normandy and Holand.
The style of the documentary is pretty raw I find. There is some seriously raw emotion in many of the interviewees - and not just from veterans. And also, Burns has not shied away from issues like the Americans killing Japanese prisoners, or the issue of how inept the Yanks were in the beginning of the North African campaign, cowardice among some high ranking officers, etc. I am enjoying it.