So what impact is the arrival of another high profile open OS likely to have on the mobile market at large?
Giving the OS away for free should drive Symbian adoption - and that could put pressure on Microsoft which charges a royalty fee for its OS, according to Milanesi.
It is also likely to increase penetration of open mobile devices in the market - which will shift the focus onto user interfaces and mobile services as differentiating factors between handsets as open platform devices proliferate.
She said: "If you look back a couple of years ago, proprietary platforms were the majority and in the mid-tier continue to be, whereas now you see more and more a shift towards open platforms… If you look forwards, in 2015 or 2017 that's going to be pretty much the whole market."
It may also mean cheaper hardware in the long run.
Byrne added: "If they're all using the same hardware and software platform that will mean hardware costs can decrease and the OS and the UI will become more standardised - although there will be a degree of modularity.
"Differentiation will be carried out at a higher level. It'll allow the device vendors to focus on adding improved functionality to, for instance, media players or software that is more visible to the end user and allow perhaps a more stable base beneath that. But it will allow those device vendors to innovate perhaps more strongly to ensure their brands are protected in that area."
And what about Google's Android? Is the Symbian Foundation an Android killer?
Not necessarily, according to Milanesi, because - if the Foundation makes developers wait until 2010 to use its open platform it may have already missed the boat. "There's a window of opportunity here they need to grab as far as how they're going to time it," she said, adding: "Two years is a long time in this industry."
However, the Symbian Foundation may well have the edge over the upstart as Ovum's Leach points out. "[Google has] bitten off quite a lot with Android," he said. "And I think that the LiMo Foundation and the Symbian Foundation are better set up to be successful. I think Android's a more of a wild card to be honest.
"It's taken Symbian 10 years to get to where they are now - Google are being very optimistic about what they can achieve with Android."