Sony Ericsson and Symbian
The news, if confirmed, will come as a blow to the Symbian Foundation and, to a lesser extent, Nokia. For the short term it will leave Nokia, Fujitsu and Sharp as the only companies known to be working on future Symbian handsets. Sony Ericsson (as Ericsson) was one of the founding members of Symbian and has a long history with the platform, from UIQ up to the more recent Symbian^1 Vivaz handsets.
At this stage it is not possible to rule out future Symbian devices from Sony Ericsson altogether. Unlike Samsung, Sony Ericsson remains actively engaged with the Symbian Foundation. For example, its representatives were present at three of the four council meetings in September (Release Council, UI Council and Feature and Roadmap Council). This would suggest a continuing interest in the platform. A likely scenario is that Sony Ericsson is keeping its options open and may release a Symbian^4, or later, device.
Impact on Symbian Foundation
The Symbian Foundation was set up with the goal of making it more palatable for manufacturers, other than Nokia, to get involved with the development and direction of the Symbian platform. Nokia was always going to be a dominant player, but the hope was (and is) that other manufacturers would also get involved. This is reflected in the way the Symbian Foundation is funded, with the operating costs being shared equally among the device manufacturers on the board. Clearly manufacturers not producing Symbian handsets will question the value of remaining on the Symbian board.
In practical platform development terms there will be little impact on the Symbian Foundation in the short term. Neither Sony Ericsson or Samsung are making significant coding contributions to the platform. The vast majority of engineers working on the Symbian platform come from Nokia, with the remaining ones coming from a handful of companies with a vested interest in the Symbian ecosystem.
Nor will there be a significant impact on sales numbers. The impact, in some sense, will be more political than anything else. It will inevitably be contrasted to the Android platform, which has been able to attract a great number of manufacturer partners.
Given the well sign posted changes (AVKON to Qt) from Symbian^3 to Symbian^4 it is perhaps not surprising that manufacturers have chosen not to adopt the Symbian^3 version of the platform (a certain amount of investment would be wasted). As such the critical time for the Symbian Foundation comes with the release of Symbian^4 and Symbian^5 next year. If it is unable to attract new manufacturers, or win back Samsung or Sony Ericsson then it will inevitably faces questions about its future structure.
Ironically the future of the Symbian platform itself is looking rosier than it has for the last few years. Nokia has made it very clear that it sees Symbian being its primary platform for the foreseeable future. NTT DoCoMo / Fujitsu are using it as the basis for their next generation mobile platform and are very active with the Foundation's processes. Nokia's recently announced Symbian^3 handsets (N8, C6-01, C7-00 and E7-00) have been well received and the Qt and WRT led rejuvenation of the developer tool chain is winning rave reviews.