The new version further improves Opera's Speed Dial feature, which enables quick access to your favorite sites when you open a new tab. Now, Opera has added extensions in the mix, letting you customize your Speed Dial favorites into more than static links. For example, Opera has created an extension that gives you the weather forecast for a specific location (instead of just providing a link to a weather website).
To create your own extensions, you need basic web development skills, which includes some grasp of HTML/XML. Documentation for developing Speed Dial extensions is available here. If you don't feel up to it, you can simply download Speed Dial extensions from Opera's extensions catalogue.
The other improvement of note is password synchronization, which can now be done securely through Opera Link. This means that your passwords (as well as bookmarks, Speed Dial, search engine preferences, typed browser history and notes) can be synced across several Opera installs.