According to Andreas Constantinou, research director at Vision Mobile, an open source version of the Symbian OS could have one distinct advantage over Linux-based systems; "The Symbian Foundation's platform will be backwards compatible with Symbian OS 9, S60 3rd Edition. This backwards compatibility warranty isn't offered by either Android (which may suffer from fragmentation by design) or by LiMo (which effectively standardizes middleware and kernel, less so the application environment)."
Microsoft will most likely join the bandwagon as well with an open source version of Windows Mobile, or at least offer a large chunk of the more important parts as open source to heed development and compete with Linux and Symbian. Constantinou commented; "Windows Mobile is the only licensable OS for mid/high-end phones which doesn't have a consortium-based contribution model and an open-source-like license (apart from selected parts of the Windows CE source code which are under varying Shared Source licenses). I would expect Microsoft to react in the next quarter by open sourcing more of Windows Mobile."
Another key component in the battle is the fact that unlike LiMo, the Symbian Foundation will be controlled by a single player- Nokia. This governance model is effectively similar to the Open Handset Alliance, which is controlled by Google, and the WebKit browser core development, which is owned by Apple (although the underlying mechanisms are quite different in each case.) This may have a significant impact on the direction any of which may go in the future. Only time will tell which one emerges on top.