Actually our brains are getting bigger for the first time in centuries. Our brains are very slowly starting to expand on the sides, last I heard.
Our heads are not getting "bigger," as much as getting "wider." The male and female brains work a lot differently. Genetic engineering might put
us both back on the right track. Men have better spacial recognition, while women can multitask and have better connection between the hemispheres
(corpus collosum (sp?)). If we wired our brain correctly, we would learn much faster and store things more efficiently. We might be able to use all
that left over space
Larger eyes can have an advantage, but more importantly, how our brain interprets the signals our eyes receive will determine whether we can see more
colors, infrared, ultraviolet, and a large spectra of other wavelengths. Essentially, larger eyes will allow us to see a wider area at one time...
along with eye positioning. Eyes too far apart lose the 3-d effect.
Our overall body stature is not likely to change that much because certain body types are seen as more beautiful or able to survive. Taller men,
perhaps unfairly, are seen as more attractive, virile, and powerful. These allow mating possibilities to be more readily available. Evolution would
not get rid of these things unless there was a drastic change in nearly every aspect of living. More surface area helps the body to sweat more. More
hair keeps the body warm. Whiter skin allows for vitamin D to be formed from sunlight. The layer of fat attached to our skin allows for better
swimming and thermal control. The list goes on and on. We are designed very well and the future will not change us unless we have to adapt to a
terribly different environment.... perhaps space.