Typing 2.0

I was at the Henley KM Forum yesterday, and we had an interesting side-conversation about the increasing importance of touch-typing in today's world of multi-synchrouous chats, on-line swarms and text-based social media. How much of a business disadvantage will 30 wpm be vs 50 wpm in the future? (Or 35 wpm, then 15 seconds of correction, as it is in my case!). [My mum has even started emailing me to point out my typos on my blog and website!]

Will accurate speech-to-text interfaces replace it in the future, or should my children learn touch typing as a matter of urgency?