The XO-3 supports many use scenarios to fulfill kids’ learning needs: from horizontal book mode to portrait reading mode to multi-touch--so many hands can play and learn together on the same screen--to a full-touch keyboard and a back facing camera. " onelaptop.org
Existing features (reliable list because I have an XO) - Wi-fi, 3G capability, audio-video, touch screen, open source code, a huge community of Indian techies and a galore of other goodies.
Cost ? Immaterial as OLPC India also provides for an option that is successful in the UK and even the World Bank subscribes - a lending library.