Unfortunately, there will be no cast album. Roundabout is non-profit and does not do soundtracks (Pajama Game was personally produced by Harry Connick Jr. his-self). The Weill Foundation seems to be focusing on the upcoming spectacular Klaus Maria Brandauer version at the Admiralspalast in Berlin this August, and surely doesn't want to glut the market. In addition to Cyndi's own label commitments, Nellie's contract problems with SONY only add to the confusion.
So this Threepenny will go the way of all true theatre-- and disappear the way the voice of Jenny Lind did.
I have to warn you, though, andreabicsotti... If you are stuck on the Blitzstein version from the 1950's, you most probably would not like ours. It is a new translation and adaptation, and probably truer in spirit to the original German text, profanities and all.
If, however you revel in onstage oddities, especially since they happens to rarely on Broadway, and understand that-- though Blitzstein's translation is excellent, it is but one of the many versions out there, you will appreciate.
I might also suggest you pick up the 1996 Domar Warehouse version on CD, for yet another brilliant take on this classic.