The voice of DotA 2
There you have it, straight from the Duke's twitter account. With such a star voice actor lending a hand to the IceFrog's project, we can safely assume that it will be a very epic game indeed.
To check out what Jon St. John has done in his voice acting career, check out the youtube video below, which contains his most famous voice yet, the voice of Duke Nukem.
Twitter - Jon St. John's twitter account
JSJPod - Jon St. John's company website