For the DVD info, go to Amazon.com you can preorder it and get Free Shipping; the release date is Dec. 9th.
The DVD includes three Episodes never shown in the USA as well as lots of other goodies!
For movie info just go to Google and type in Firefly the Movie and you will get lots of articles about the upcoming production.
Oh and here is some bonus info. Adam Balwin, the actor who plays Jayne, posts over at the Fox Firefly Forum. Yes, it is really him! All of the actors from the show were given accounts with official designation symbols so the fans would know they are really the actors posting.
Anyhow, Adam posts a lot of political threads and, (get this) is a no-apologies-fire-breathing-conservative-Republican!