The Windows 7 Enterprise powered machines will have 2GB of RAM and a six-hour battery, along with productivity software like Microsoft Office, the Adobe CS4 suite (good luck running that smoothly on the Atom platform), Apple iTunes and other content geared to students. It's mentioned that Windows 7 plays a very significant role due to its security and built-in features like the AppLocker and the System Center Configuration Manager, used to restrain what software is installed on the machines and to distribute updates wirelessly to the devices. Additionally the netbooks will carry passive RFID tags and other security implemented at the BIOS level. This in case the netbook is lost or stolen, it can be remotely disabled.
All in all, sounds like a promising scheme despite the enforced restrictions. One word of advice: Touting anything as unhackable is never a good place to start (although in all fairness there is no direct quote calling the plan as such, besides the article title).