NBC Uni owned Syfy announced at San Diego Comic-Con that it was picking up Eureka for a fourth season. I have not seen the press release yet, but we'll post it if they ever issue one. The network has ordered 22 more episodes, so we can likely expect at least 2 more "half" seasons.
This summer Eureka moved from Tuesday nights to Friday nights (last Friday, July 17, it had 2.68 million viewers). I'm happy to hear it has been renewed. It's one of the shows I caught up on that I likely would never have watched if not for this web site and hearing from fans, and now new episodes are automatically captured on the DVR. It's a silly and goofy show in most ways, but it's fun and I enjoy the characters as silly as they are at times, so it's good to hear the news of a pickup for a fourth season early into the third season.
I know the picture above is a bit dated (Sci Fi, not Syfy!), I'm still making the brand transition