This is true. While speaking to an online crowd isn't quite as immersive as speaking to a physical crowd, many of the aspects remain the same, which would allow people to practice them. For example, it would help people with the actual speaking process. Furthermore, I think for a lot of people, internet people are still seen as a conscientious objective party whom will react to the speaker, and as such that fear of consequence yet satisfaction from feedback is still very real to us.
I'm noting that a higher number of people have said they'd be willing to give a speech than previously anticipated. Perhaps we should do a semi-formal test night, where people don't need a speech: they can just come up and speak about anything to get a feel for it. I'll probably read a Cracked.com article or badassoftheweek.com article for kicks. I've always wanted to do that.