Footage from the upcoming “The X-Files” sequel has been leaking to the web for months, but at the recent WonderCon in California, fans had a chance to see the first official teaser for the movie. And the preview certainly excited a lot of fans, with the crowd whooping and cheering as Gillian Anderson and David Duchovny make their appearance. As with other snippets of information on the sequel, the trailer offers no details as to what the plot is about. In the teaser trailer, a line of FBI agents (led by Billy Connolly) trawls a snowy plane looking for something … or someone. As the reach the middle, they suddenly find what they are looking for, exciting Connolly’s character to no end. “The X-Files 2” is scheduled for release Jul. 25, 2008.