I am a huge fan of voicemail transcription and I think it should be a default feature from all carriers. Sprint is moving in that direction with their Sprint Voicemail-2-Text service powered by Nuance Communications. The service is only for BlackBerry users and has been in testing since at least June of this year. It lets you get your voicemails as either emails or text messages and respond to the messages.
Sprint Voicemail-2-Text service for BlackBerry available now to all for $1.99/month after a free 30-day trial which you can pick up at m.getjar.com/mobile/72278/Voicemail2Text. Sprint Voicemail-2-Text is supported on the BlackBerry Bold, Curve, Tour, Style and Touch (I am guessing the 9850) models. Check out the details on Sprint’s website or Nuance’s press release.