Dodge, Siri is actually reading some Wolfram Alpha responses now. Not the long ones but shorter ones like equation results, birth dates, occupations, ages, currency conversions, etc.
She'll go "here you go:" then read the result. Not sure if this is for all Siri's but it's doing it for me on iOS 6 beta 2 and I know she didn't do that before.
Siri always did that, here's an article from shortly after Siri came out:
http://www.tuaw.com/2011/10/28/10-cool-things-you-can-do-with-wolfram-alpha-and-siri/