When it comes to wheat, one of the things nobody is mentioning is the protein per calorie content. I'm having a hell of a time consuming 180 grams of protein per day and I'm looking to my carbs for a helping hand. There's 3 times as much protein in say whole wheat bread or spaghetti than there is in say rice or potatoes. Right now the only thing that can compete with wheat on this basis is legumes... oh and I also discovered wild rice is pretty good too.
Anyway, just a note on the pro-side for wheat. Its the biggest staple in the world and I expect this is the case for a reason -- compare the size of people on this staple (NA and European) to the size of people on the rice staple (Asian). Coincidence? I don't think so.