One can only assume the Opera browser will be more satisfying than, for instance, the Sega Dreamcast Web Browser. I have to admit, back when I was a poor college student who couldn't afford computer parts when something broke I did get stuck using my Dreamcast as my primary home source of internet access for short periods of time. But it wasn't pretty, and while you can streamline the browser somewhat, there's only so much you can really do with the low definition TVs that the Wii are going to support.
Which leaves me wondering: how many people with a wireless router in their homes are going to want their internet experience to come on a big screen with a low resolution?