Excellent post as always, thank you.
One thing I'm curious about in this area, but haven't seen a lot on, is the plan for educational content for all of these devices. There are many criticisms one may lob at OLPC thus far; for me, the lack of effective content strategy and integration into lesson plans is the most important one. And to the extent that the educational content sources (lessons, articles, whatever) are derived from online sources, what are the plans to introduce connectivity into classrooms? (And how does that help for 1-to-1 initiatives where students can take the devices home - but don't have internet access there?)
I find the results from Worldreader to be quite interesting in this respect. You might argue that their initiative is very content focused (1-to-1 distribution of basic Kindles with preloaded books - so kids can consume these materials anytime, anyplace). Worldreader has shown a statistically significant positive impact on reading scores - I'm not aware (perhaps I've missed something though) of many other ICT initiatives that have shown considerably better, clear positive results in impact studies.