From the blog entry:
The Opera Mobile team is happy to announce an updated version of Opera Mini 6.1 for Symbian.
In this release we added support for brand new Symbian Belle devices and improved integration with half-screen keyboard on phones running Symbian Anna.
To get updated please visit http://m.opera.com from your Symbian phone or http://www.opera.com/mobile/download/pc/ from PC.
Opera Mobile also has a similar update to its v11.1 browser.