Nothing has been heard of the series since then–until now. A new single episode has been released and can be viewed on Crunchyroll. It is a self-contained story so you don’t need to have watched the original series to enjoy it. Even better, we are promised another season of Mushishi beginning this Spring.
Mushishi chronicles the adventures of Ginko, a wandering 19th century naturalist who studies strange unearthly creatures called “mushi.” These are not usually inimical to humans but are not usually friendly either, and they can be very dangerous to people who don’t understand them. Ginko has a scientist’s love for the things he studies but he also tries to help the people who have been harmed by mushi.
The original series seems to be available for legal streaming only in a dubbed version, which means that you would miss out on the excellent original soundtrack. Unless you are a fanatical subtitle-hater you would do much better to buy or rent the DVDs and watch it with subtitles.
Or you could wait until April when the new season comes out. If past experience is any guide there is a good chance that Crunchyroll will offer the first season at the same time that it streams the second.