Because I'm pretty sure this is the end-all diet of diets.
Maybe. I hate to say it, but if we ever create the singularity or something and we live in virtual reality, I'm loading up on virtual doughnuts.
I wouldn't say that the Paleo diet is "a diet"; I'd say that it's "our diet" in the true sense of the word, meaning what we evolved to eat as opposed to a distorted eating regime skewed to cause weight loss.
Aaron, The word 'diet' simply means what one eats. Dogs have a 'diet', cats have a 'diet,' even my goldfish has a 'diet.'
And, I was opening the question up not because I don't recognize that this is a lifestyle, but because I recognize that in every sense of the word it is a 'diet.'
However, socially we have given the word a negative connotation, saying that 'dieting' is a bad thing, or that one can be bad or good.
I'm asking as an open question for people to answer, not scrutinize my intentions. My life choice is to eat and live the Paleo lifestyle. And be on the 'Paleo Diet.' Because 'diet' is still the correct term.
But thanks for the response nevertheless -Karen
Michael Pollan has a great bit about how nutritional science is about where medicine was in 1600 or so: Some solid basic knowledge, a lot of theories that seem to make sense but will look silly in time, developing at a fast pace, and fascinating to watch... but all in all, kind of scary and you wouldn't really want to stake your life on it. The fact is, we know squat about human nutrition at this point, and while paleo makes a lot of sense as an approach, who knows if it will really be "optimal" given another 50 or 100 years of knowledge?
Definitely; through Nutrigenomics (http://en.wikipedia.org/wiki/Nutrigenomics):
Nutrigenomics is the study of the effects of foods and food constituents on gene expression. It is about how our DNA is transcribed into mRNA and then to proteins and provides a basis for understanding the biological activity of food components.  Nutrigenomics has also been described by the influence of genetic variation on nutrition by correlating gene expression or single-nucleotide polymorphisms with a nutrient's absorption, metabolism, elimination or biological effects. By doing so, nutrigenomics aims to develop rational means to optimise nutrition, with respect to the subject's genotype.
By determining the mechanism of the effects of nutrients or the effects of a nutritional regime, nutrigenomics tries to define the causality|relationship between these specific nutrients and specific nutrient regimes (diets) on human health. Nutrigenomics has been associated with the idea of personalized nutrition based on genotype. While there is hope that nutrigenomics will ultimately enable such personalised dietary advice, it is a science still in its infancy and its contribution to public health over the next decade is thought to be major. 
The fact is that Paleo (and the whole of Nutritional Science) is still really quite primitive. We all do have unique responses to food and the environment, and Paleo is simply just the best (by far!) "general prescription" of what to eat for the average human. There is still much variation amongst us, some are better tolerant of grains like for example the many centenarians out there that lived on wheat daily their entire life and made a ripe old age that many Paleo follows may not achieve. Then there are the various tolerances to dairy/lactose, and nightshades, supplements and a whole host of other individual variances in how we respond to foods.
The future holds some exciting advancements for us, especially those of us already interested and learned on these subjects. In 5-10 years full genome scans will become the norm, and it will be the self-directed/interested pioneers like ourselves that will drive the new wave of personalised medicine, at least initially. It is already happening to some degree, and it will continue to become more and more advanced as we collect more data and the huge potential for uncovering information is realised.
A great example is this:
UK Women at Risk from Vitamin A Deficiency
ScienceDaily (Nov. 18, 2009) — Almost half of UK women could be suffering from a lack of vitamin A due to a previously undiscovered genetic variation, scientists at Newcastle University have found. The team, led by Dr Georg Lietz, has shown that almost 50 per cent of women have a genetic variation which reduces their ability to produce sufficient amounts of vitamin A from beta-carotene.
Through the many genetic testing companies offering analysis like 23andMe (https://www.23andme.com/), it is already possible to have your genome scanned (SNPs, not a full scan) and find out many tidbits of information related to your health, like for example if you have the gene variant above which makes you inefficient at converting beta-carotene to Vitamin A. If you do, then you would ensure your diet included preformed Vitamin A such as from ingesting organ meats or cod liver oil for example instead of relying solely on carrots and vegetables. So the age of personalised medicine is already here to some degree, it is just in the very early stages.
Very exciting stuff!