Essentially, no. However, under the beta 3 version of the upcoming release there is some rudimentary support. But because of the way the "commercial concerns" are busy stripping away our fair-use rights through copy protection and DRM, this leaves the open source community out in the cold!
So the only way BD and HD DVD can be played with beta 3 is it automatically rips the whole disk to HDD first, and the decrypts and plays it from there. But the menu system doesn't work, just basic play functionality.