Why did Central and South American nations participate in WWII?
Excellent. The question itself was a bit squishy, but the answer was absolutely wonderful. I wasn't even sure how to begin Googling for it.
How could a chariot work against a phalanx?
Excellent. The question was truly puzzling, as presented. The accepted answer (with a bit of help from commenters) actually dug up and corrected a vital piece of wrong info in the online sources. Perhaps a wee bit long for my tastes, but that's just my taste. Our answer was the third hit Google gave me.
What is the longest running legal case?
Excellent again. The question was not only quite straightforward, but showed some research (take note, everyone!) We were only about the 8th hit on Google, but our accepted answer was a better one than any of the preceding 7 (with our runner-up matching the best of the other 7 Google hits). My only complaint is that the questioner didn't accept an answer. (I almost bumped it down for that, but we otherwise covered ourselves in glory here, so I just couldn't.)
How much did we know about heredity pre-Mendel?
Needs Improvement. We were not any of the first 20 hits I got on Google, and that's probably for the best. The question is legit. However, there's only one answer. Its an OK answer. Not sparkling, but OK. It could really use some competition. The google hits I got were full of really good information (along with the exact question on ask.com, with its typical horrible answer). We can do better here. This was also the first of the example questions I was unfamiliar with, so perhaps a lot of that is my bad.
When did Japan and the Three Kingdoms of Korea first meet?
Excellent. Wonderful question. Showed its research and where that research failed. Certainly not trivially googleable. Great (although again way too long) answer. Could use another answer, but then in this case perhaps the accepted one is right, so no other answer really needs to be created. I was on the fence about this one, but I'm marking it up to "excellent" because I don't think you can find better on the internet at large without doing a lot of research yourself.
Which countries protested against the Anschluss?
Needs Improvement. The problem here is that the question is really squishy (as the one answer rightly pointed out). The answer is no better though, as it presents novel (to me) information with no backup whatsoever. This was pointed out in the comments, but never rectified. Disappointing all around.
What book on liberty did Lord Acton not write?
Excellent - The question looks weird at first blush, but is fair enough. I'm not sure how to go about Googling for it. On the plus side, it has two answers, one of which appears to be 100% correct and very well written. I even upvoted it at the time. Sadly, the other answer was clearly written by a total buffoon, and should probably have been deleted.
I do know that you can't easily find the answer outside of our site, because I tried and failed miserably. :-) So I think despite having only one good answer, and that other blemish upon the face of our stack there, I'm marking this excellent as well.
Pre-WW2 location of Skalat
Satisfactory - The question is the weakness here, as it turned out to have the answer right there in the wikipedia page. However, the answer is great, in that it points this out and distills the important info from that page nicely. There's no other answer, but there really doesn't need to be. We were the second hit I got on Google (the first being the wikipedia page in question).
What wiped the Buddhism traces from Kerala History?
Satisfactory - The question was probably the weakness here too, in that I found the answer explicitly stated right in the Wikipedia entry I got from my first Google hit. Our answers didn't make Google's first page of hits, and neither was accepted. Both answers themselves look pretty good to me.
PANDA Source Analysis
Needs Improvement. I'm not saying its horrible. Its just that the answer has not been accepted, and could probably use some more attention. As I mentioned in the comments, the nature of the question makes it ungooglable.
In aggregate, this is the best site-eval I've returned for this stack yet, by far. Good job everyone!