We've been tipped to the recent release of libdi, the Wii homebrew community's new DVD access library, and the DVDX installer from Wii homebrew source Hackmii. Erant of Hackmii says,

As you all know, I’ve been working on libdi (or the DVD Access library) for a while now. We had some problems getting it out to release because of the difficulties we encountered while writing the second part of this topic. The DVDX installer instead will install a small, hidden, channel on your Wii that allows you to read DVDs on an unmodified system. It is not an installer for a patched IOS. You may however need one, depending on your system.

Now there's still a way to get DVDX to install on modified systems, but you'll have to get the patchmii as well before the DVDX Installer. Developers are encouraged to practice with the library, using the DVDX extension as a way to read data from standard format DVDs.

For example, developer dhewg has come up with a sample homebrew app based on libdi - a full-featured media player. More updates on the homebrew scene as we come across them.