Nigel Allen on YouTube or iTunes. Content is entirely airgun-related. Excellent production quality and content.
American Airgunner The show airs on the Sportsman Channel. Also, most episodes are available on PyramydAir.
Not specifically for airguns, but Target Shooter has at least one airgun article in every issue. Always an interesting read even for the powder-burning articles.
Another general magazine with some airgun articles and all (most?) of the NRA event/match information is Shooting Sports USA.