"Who Needs Him?" is the most exciting extra.
It's the song that Sondheim and Styne wrote for Rose to sing when Herbie walks out. But they quickly realized that Merman didn't need an angry/sad torch song midway through the second act, when she was going to explode with "Rose's Turn" a little later. It just held up the pace, so they put in the little reprise of "Small World" and let the show move on to the strip scenes.
So no one ever heard Merman sing it. (I once heard Sondheim sing it, in a classroom setting.) But it will be thrilling to hear Patti sing it!