The Miiverse is now accessible via PC and mobile devices. Just as promised, folks can now peruse Nintendo's social network can from web browsers.
Functionality is somewhat limited at the moment. The service is presently in beta and users can't reply to threads just yet. Rest assured though, that ability will be made available at a later date.
To view the Miiverse from a browser users will need to create a Nintendo Network ID on a Wii U console. Those without access can still get a feel for the community as a number of threads are available via a sampler.
Nintendo will also bring the Miiverse to 3DS sometime later this year.