If you thought the HD rollouts from Comcast were dwindling down, you've got another thing coming. It appears that Richmond, Virginia will be picking up four newcomers as well on April 15th, notching AMC HD (218), CNN HD (234), History HD (237) and Animal Planet HD (241). Also of note, another foursome of channels -- History Channel, Cartoon Network, G4TV and ION -- have gone all digital. Got any more Comcast? We're sure users all over the US would love to get in while you're being generous.