Jott really had a good idea when they launched back in 2007. It let you call up or send voice messages from their BlackBerry app that would automatically be transcribed to emails, notes, or other services. A bit back they bit the bullet and started charging for their previously free service which caused many users to stop using it including myself. At $4/month minimum many people could not justify the cost.
Nuance is the company that powers the voice dialing on the BlackBerry OS so this is not a new territory for them. Hopefully they can find a way entice people to continue using Jott. Until then I have been recommending Vlingo.