I am sorry to hear that Geneon has decided to stop publishing Region 1 DVDs (via Don). Of all the North American anime publishers, Geneon probably has the best taste. This means that some of the best anime series are going to become hard to obtain, at least for a while.
Geneon’s licenses and master recordings are valuable properties. Barring unexpected legal problems somebody will probably pick them up, so we may hope that completed series like Shakugan no Shana, Haibane Renmei, Chobits and Kamichu will be available before too long under another label.
Things look worse for series that are not yet complete. For example only one disc of The Story of Saiunkoku has been released so far; most of the remaining episodes are probably not translated yet, let alone dubbed. This is a worthy story but since it lacks fan service or constant violence, yet is over the heads of most children, its mass appeal is probably limited. It is quite possible that the rest will never be released.