Voiceprint backup to password resets?

Microsoft has come up with another clever idea. Voiceprints to reset passwords. This is using biometrics that would definitely prove to be useful.
Bruce Schneier:

But the real beauty of this system is that it doesn’t require a customer support person to deal with the user. I’ve seen statistics showing that 25% of all help desk calls are by people who forget their password, they cost something like $20 a call, and they take an average of 10 minutes. A system like this provides good security and saves money.

Via Schneier

Personal note: My question is, what stops someone from using a recording? In cellular technology, a generic model of a voice print is used, and when a person speaks, that voice print is modulated in a digital format. There is nothing to say that a person couldn’t get the modulation patterns from recording a person’s speech and then use a generic voice print to do the play-back. That would give practically identical speech patterns.