I saw this afternoon's performance, and I'd say that 98 percent is just as Wilder wrote it. The only significant differences I noted are along the lines of a quote from bell hooks replacing one from Plato. There are also brief updated contemporary references, like to popular plays - Vanya and Sonya instead of Peg o' My Heart, etc. And the last act is done in Civil War costuming, which is probably not what a person would usually expect.
Anyway, regarding the awards discussion above - I didn't even think the performances were good in the first two acts, let alone award-worthy. Almost everyone has been obviously directed to play broadly and cartoonishly so that, for me, there was almost no compelling drama and few laughs. I kept thinking, this is the Wilder play where they should have brought in David Cromer -- it could be wonderful in the hands of someone who values subtlety and realism.
And then, in the third act, it was like my wish came true - the tone was totally different, subdued and natural. They still missed some of the laughs but did really well with the drama. Also, throughout the show, the set design, very large puppets, and other visual aspects were first-rate.