I always felt that diversification is one of the things needed to keep the comics industry from stagnating.

DC has always had the most diverse comics in terms of genre..at times they even used it as a selling point ("More than  just super-heroes...but we've got them too!)...the only time Marvel was more or less equal in this area was probably in the bronze age and perhaps the Atlas era.

Sure, DC has always been one of the larger comics companies in terms of output, so it can afford to do its part in terms of different genres but the fact that Marvel usually chooses not to nowadays is one of Marvel's biggest faults in my view.

I think that among the smaller companies (who can't really compete against the Marvel and DC super-heroe universes anyway) Dark Horse (similar to Vertigo) does a great job in terms of genre diversification which is still mainstream enought not to corner itself into a marginal niche and deserves the acknoweldgement for it. IDW probably comes second.