You can now pre-order Season 5 of Buffy the Vampire Slayer at amazon.com or amazon.ca. The set is due out on December 9th. (And yes, I very much appreciate it if you pre-order via my links, as I get a small cut of what you spend. Thanks in advance if you do so!)
They're also releasing a set that contains seasons 1-4 of Buffy on October 28th. Great deal if you haven't already bought the first four seasons (heck, even if you've already bought one of 'em).
I'm working on an update of my TV on DVD page right now and also on a new Canadian version (all the links would be to amazon.ca).