Nokia has outlined the risks of its decision to partner with Microsoft in a regulatory filing that highlights many of the issues raised by critics over the past few weeks.
The primary issue is the hiatus period before it can launch devices running Windows Phone 7 - a period that condemns the company to another year in the smartphone wilderness.
Rivals will be quick to take advantage, particularly Nokia's closest competitors Samsung, which has launched a program to woo Symbian developers to its home grown apps platform, bada.
While Samsung's flagship Galaxy family runs Android, the bada-based Wave range has also contributed significantly to the Korean giant's recent success in smartphones.
It is geared to mass market smartphones with ease of use a priority in its widget oriented user interface. It is also susceptible to customization by carriers, and these characteristics make it a good fit for Symbian developers.
Samsung denied it had a formal program of strategic hiring from Nokia, despite reports that it has sent a letter to a group of Indian engineers working for Nokia welcoming them to the bada world. Many believe the letter is the prelude to a broader campaign to boost bada's skills base courtesy of Nokia and the wider Symbian community.
Moves by rivals to maneuver their operating systems into the space left by Symbian will be one of Nokia's key challenges until it can launch its WP7 range, which will be late 2011 at the earliest (though it will have its MeeGo device before then). And of course, that timeframe lengthens if the first WP7 product fails to be a knock-out.