"Way Over Yonder in A Minor Key" is pure Guthrie - lyric and music. Bragg & Wilco nailed that one. I know of at least one other group that is now performing that song.
As for the music being "un-Woody" I don't find that to be a problem. Woody wrote so much material and some of it was not intended as music but rather verse and poetry.
I wasn't blown away by many of the interpretations on Mermaid Avenue but I appreciate the effort and care that went into it. Bragg was very respectful of the music and between him and Wilco they opened up the music to a new generation and audience that normally would not be exposed to Guthrie's music.
Also, the Guest statement that Arlo doesn't play Woody's music is false. Arlo has covered a number of his father's songs and ALWAYS includes a couple in concert. I don't think anyone would expect Arlo to do more than that.