People ask me all the time how twitter could be used in education...oh, I don't know...this seems to be a pretty creative use to me. Of course with all eLearning tools, your learners MUST already be there. If you have an audience already utilizing twitter then this makes perfect sense. It might also make sense if your goal is to combine a history lesson with a technology lesson. This could get twitter haters to see the technology in a whole new way as well.
Its all about being creative and seeing things differently. Stop trying to use twitter as a replacement for your chalkboard. That won't work...if you haven't already found out.
You've got to engage with new media and just use it for a while before you can start to see creative learning solutions like this. I'm looking forward to seeing how the story unfolds.
DevLearn 2010 Conference and Expo - November - San Francisco, CA