"A source close to the Wii Opera project", as they've wished to be identified, has given yours truly a little bit of info on what you'll be able to expect from the trial version of the Opera browser that's being made available to Wii owners this Friday.
Several key features are expected to be nerfed from the trial build. Most notably, Javascript support.
Other things you'll notice with the trial version: Flash may not work correctly. It appears that Opera is custom building their Flash plug-ins to limit the security exposures that the plug-in presents.
Widget support is being hurriedly rushed in a desperate attempt to get it included in the Wii Browser on Friday, but it's not expected to be made available. Support for the Ajax technology is expected to work fine, however.
In fact, this is less of a "trial" and more of an "Open Beta".
Source
Sounds like its gonna be pretty lame.