I agree that this feature has great potential, baseball being the perfect radio sport.
During the past couple of days I've been playing around with different voices and also the OOTP TTS text file where you can alter pronunciations (located in the 'misc' folder).
Couple of short videos I've made using slightly improved voices from the default MS ones:
OOTP TTS IVONA Joey - YouTube
OOTP TTS IVONA Eric - YouTube