Hold on to your S^3 handsets a little longer because it looks like Meego-Harmattan's (Nokia N9) Swipe UI will be coming to Symbian Belle (excited much!).
A tipster from My Nokia Blog spotted a document on developer.nokia.com regarding symbian design guideline that talks about integration of new UI model for symbian post Anna utilizing Qt Quick components.
Symbian releases after Anna will introduce a number of changes in the design and user experience. Qt Quick components 1.0 for Symbian is the first implementation that follows the new Symbian design guidelines. By using Qt Quick components 1.0 for Symbian, applications will not only have a fresh new look, but will also comply with the evolving Symbian style.I will be holding on to my N8 even if I buy a Nokia Windows Phone 7 in the future. Aside from N8's awesome camera, I'm also looking forward to Symbian belle's new UI even before information about Swipe's integration was heard.
From My Nokia Blog
From Developer.Nokia.Com