This Forbes article suggests that introverts make better leaders by playing to their strengths, rather than fighting them--and cites a lot of speaking skills to bolster its point:
By using a "think first, talk later" approach, introverts give themselves time to ponder, while appearing measured and thoughtful; this also gives subordinates a chance to contribute and can keep leaders from making mistakes by jumping in too fast. They ask questions and take an in-depth approach to conversations, yielding more learning and understanding. They appear calm, usually through anticipating issues, practicing what to say, and getting themselves in the right frame of mind before communicating.
The Eloquent Woman tipped me off to another article about introverts, speaking, and leadership styles. It's easy to think of the introverted style as being a handicap, so it's nice to see a catalog of the ways that introversion can be an asset. Click through for the whole post from The Eloquent Woman and for the original article from Forbes,