Hi,
In my opinion divx and other codecs will only be on the extender part of xbox, after the V2 extenders are widely available.
Right now people are paying premium for the V2 extenders, and the way to sell those, besides being silent, smaller and consuming less power, (ok, they're wireless too, but I don't believe in wireless extenders too much) is their hability to play all the codecs people want. I think Microsoft might have some kind of agreement with linksys, d-links and the others, not to bring this features to xbox for some months, to let them penetrate the market. I think Microsoft is really interested in having hardware partners for the extenders, so Xbox users must wait. In time, videos encoded with this codecs, will be available in the Media Center interface as they are already outside of it.
Nuno Silva Microsoft Student Partner Lead Portugal