Tablets in Rural South Africa. Although not a project on the scale of what you've mentioned above (yet), the CSIR Meraka Institute is in the process of piloting (Android) tablets in Cofimvaba, one of our (very) rural school districts in the Eastern Cape. The project is being driven by our Departments of Science and Technology, Basic Education and Rural Development. It is currently part of a much larger initiative, Technology for Rural Education Development (TECH4RED), which aims to contribute to the improvement of rural education through technology-led innovation. The aim is to influence policy via evidence-based research. We're attempting to actively build on learning from other one-to-one initiatives, whilst customising approaches based on our particular context. The output will be a replicable model for large-scale mobile device deployments in South Africa. We're currently in year 2 of the initiative, which we've dubbed "ICT4RED".
You mention that you don't find a compelling reason for tablets vs laptops. We're currently preparing our first M&E report on our year 1 experience. We can say categorically that our experience has been that the uptake of tablets amongst the educators and the ease of integration into actively using them in the classroom far surpasses anything we (or any of our partners) have experienced thus far. This is partly due to the fact that the jump from a phone to a tablet is far less intimidating than the jump to a laptop. The usability of tablets is a major plus point - no grappling with operating systems or external pointing devices, no trying to figure out where to find the software and how to install it, etc, etc. The fact that it's really easy to use the device's multimedia capabilities to record, video, take photos, etc. is also a no-brainer. And if you're used to using a phone's small keyboard, using a much larger touchscreen keyboard is really easy - it depends what you're used to!
For the first time, it's actually possible to focus on teaching strategies supported and enriched by technology, rather than spending days and weeks on how to use the device. Our teacher professional development methodology is based on this premise and we've had overwhelming success thus far. We literally have older "gogos" (grannies) who, after 2-3 lessons are confidently using the tablets in the classrooms - applying advanced pedagogies such as "jigsaw", "roleplay" and storytelling" techniques.
If anyone wants a blow-by-blow account of the little miracle happening at the poorest of the poor schools in South Africa, you can follow our @ict4red twitter account or search for the hashtag #ICT4RED.