I wholeheartedly believe that WotC should go to town on promoting a wide range of races, genders and sexualities to the world of D&D. The overall feel of the genre can only be improved by a polychrome approach. Let's see black dwarves, brown halflings, oriental changelings, and homosexual characters & couples presented in D&D products without any fuss. It would also be good to have a character sheet option for indeterminate gender alongside 'male' and 'female'. For example, intersex, transgender, or whatever the term du jour is.
While I wondered whether D&D's target demographic would reject a product with minimised cheesecake, I've decided that the consumer who'd refuse to buy D&D solely because a lightly chained female fleshbearer wasn't plastered all over it doesn't exist, for all practical purposes. Those who claim a lack of cheesecake is a dealbreaker will inevitably renege in the end if D&D itself is good enough. Tacky art is only needed to sell bad quality products. High quality products sell themselves, and a broad mix of humanity's shades directly boosts the quality.
Freeing up old preconceptions grants the possibility of colorful new concepts. For example, humans and human-like races don't need to be the only gay beings. Other monsters, such as dragons, can be gay as well. A group of adventurers could encounter a mated pair of dragons who are two males or two females. It may seem a minor detail, but it makes the gaming experience richer. Another long-held assumption is that drow must be black. Gary Gygax invented that attribute, but nearly forty years on there's no need to adhere to it blindly. White drow are a plausible option, and could look quite stunning in the right artist's hands. An in-game justification could be that the Underdark is a huge place and, while the first drow discovered were black, white-skinned drow can exist in other areas.
Plenty of women like D&D, or have the potential to like it. They would undoubtedly appreciate seeing the art consistently depict women as competent, dressed to suit what they're doing and not simply there to pander to male fantasy.