Cool music website, create playlists from a wide variety of popular and more 'under the radar' artists and play em on your wii. The best made-for-wii interface currently in existence, as far as I know.
A 'start page' for the wii with a number of preset links to Wiicade, Penny Arcade, YouTube, Slashdot, Wikipedia and other popular websites, a google search bar, a normal URL entry bar, and a tabbed browsing feature.
The tabbed browsing is especially useful when coupled with Finetune, since you can have your music playing in one tab while you browse on others. Hopefully Opera/Nintendo will actually include this feature in the full release. It seems like a bit of a no-brainer :/