One scenario is coming to my mind and was mentioned by Ari (although in another context): big dump of un-announced code into Qt codebase.
Nokia strives for an open approach to technology that will encourage and support innovation in the industry, enable fast adoption of new technologies and advance healthy competition. Nokia embraces open source technology and will take further the open source development culture found in Trolltech.
Trolltech has benefited greatly from the feedback the community has been providing while using Qt to develop free software. We respect the symbiotic relationship Qt has with the community and we wish to continue and enhance this relationship. (...) Nokia is committed to continue Trolltech’s current open source engagements, including honoring the KDE Free Qt agreement, and we will seek to strengthen our support of KDE in the future. As a first step Nokia will apply to become a Patron of KDE.