The guys at HippoJuice
got an interview with Futurama voice actor Billy West at South Florida Anime Supercon. Among other things, Billy speaks about a possible sixth season and says that there are talks with FOX about it. While information I got from a second source very close to the show a few weeks back did not rule out talks, I was told that there has not been any decision on the issue. So, no getting your hopes up too soon.
Watch the interview on youtube
or listen to an extended audio interview on the HippoJuice site
(starting at ca. 45 minutes into the mp3).