Well they have talked about this on Gateworld and it seems that Stargate hasn't really sold all that well in Comic Book form, however the next best medium would be novels. At the moment there is a series of novels (whom escape my memory) that's continuing the story of SGA after the event of "Enemy at the Gate." (end of season 5). There has been talk also that what was left of the SGU story wouldn't see the pages of a novel that Brad Wright wants to keep those plot points to himself for a possible movie down the road.
To me I'd rather have more Stargate in the form of novels, I also just wish that more place's stocked those books as I've not found any at my local book stores. I was able to pick up two offline from Walmart, which I think now has a much bigger selection.
I know some people don't consider what happens in the novels to be cannon, that only what is shown on the show and/or movie is canon. I'm not sure if TPTB consider the story's from the novels canon or not, but I do. It's all media from the franchise, the ONLY THING that does not fall into that is the b*****d child Stargate Infinity.