Most of the commentary has followed Valleywag's excoriation, proclaiming Songsmith the final death knell for human culture, etc. etc.
I respectfully disagree.
First of all, you can't kill something that's dead already. What universe do you have to live in to believe that Songsmith poses a credible threat to "legitimate" music production? The radio, television, internet, and every public space are currently awash in a cacophony of computer-generated, market-researched, auto-tuned, HSS-approved, virtually identical songs, produced by the same handful of engineers, for an ostensibly diverse group of artists, genres and programming formats. Everything is already compressed to hell, as well, adding dynamic flatness to the aesthetic sameness. So I fail to see how this meager intervention by Microsoft could really make things any worse, sonically.
Second of all, despite all of the factors I mentioned above, music isn't dead -- in fact, it's thriving. Never in the history of industrialized society has there been such a broad range of sonic material available at our beck and call, and never in the history of the modern music industry have musicians had so many opportunities to share their work with potential listeners. In fact, some of the most interesting work being made and shared today begins with the insipid songs and tools I have mentioned, and uses them in unintended, unofficial, critical, and resistant ways. This includes lo-fi goofing around, such as creative karaoke, as well as an efflorescence of mash-ups, remixes, glitch and the like. Valleywag untintentionally cops to this in its post, by sharing a bunch of videos in which people have run a capella versions of much-loved pop songs through Songsmith, and paired the result with the original video for the song (The Police's Roxanne, brilliantly songsmithed, is embedded below). In other words, Songsmith may be evil, but its evil may be used for good.
Finally, I am always wary of people who react to any democratizing technology by bemoaning loss of standards and quality; they sound a bit too much like Habermas bitching about the public sphere. Far too many erstwhile defenders of goodness and beauty are slaveowners in liberators' garb, too busy saving us from ourselves to give us the room to save ourselves. The truth is that most people these days don't know how to make music with instruments. It's a damnable shame, but that's how it is, and we can blame everyone -- the government, the schools, the recording industry -- except the people themselves. Clearly, a great many people remain very interested in producing their own life soundtracks rather than buying them ready-made, and I say more power to them. Any tool that helps them move towards this goal is a good tool. And if Songsmith isn't up to the challenge, someone else will come along and offer a better tool (unless Microsoft owns so many patents they effectively chill innovation).
Anwyay, that's my rant. Take a look at the videos below. Buy the software or download a hack, and play with it. Decide for yourself before you start writing society's epitaph.