I also got the impression that it was more about hardware than software. I think that the OS references are likely about stuff like Intel's and Nokia's oFono project for GSM telephony in Linux.
Open Source Software Collaboration The effort also includes technology development and cooperation in several open source software initiatives in order to develop common technologies for use in the Moblin and Maemo platform projects, which will deliver Linux-based operating systems for these future mobile computing devices. The companies are coordinating their Open Source technology selection and development investments, including alignment on a range of key Open Source technologies for Mobile Computing such as: oFono*, ConnMan*, Mozilla*, X.Org*, BlueZ*, D-BUS*, Tracker*, GStreamer*, PulseAudio*. Collectively, these technologies will provide an open source standards-based means to deliver a wealth of mobile Internet and communication experiences, with rich graphics and multimedia capabilities. Hosted by the Linux Foundation, Moblin is an optimized open source Linux operating system project that delivers visually rich Internet media experiences on Intel® Atom(TM) processor-based devices including MIDs, netbooks, nettops, in-vehicle infotainment (IVI), and embedded systems. For more information see www.moblin.org. Maemo is a Linux operating system, mostly based on open source code and powers mobile computers such as the Nokia N810 Internet Tablet. The Maemo platform has been developed by Nokia in collaboration with many open source projects. For more information see www.maemo.org. Enabling common technologies across the Moblin and Maemo software environments will help foster the development of compatible applications for these devices - building on the huge number of off-the-shelf PC compatible applications. The open source projects will be governed using the best practices of the open source development model.