I suspect this might interest some people here: for today only, 23andme is offering their full-package DNA testing for only 99 dollars (the normal price is $499).
23andme uses a genotyping process, which differs from a full gene-sequencing. From their website:
The DNA chip that we use genotypes hundreds of thousands of SNPs at one time. It actually reads 550,000 SNPs that are spread across your entire genome. Although this is still only a fraction of the 10 million SNPs that are estimated to be in the human genome, these 550,000 SNPs are specially selected "tag SNPs." Because many SNPs are linked to one another, we can often learn about the genotype at many SNPs at a time just by looking at one SNP that "tags" its group. This maximizes the information we can get from every SNP we analyze, while keeping the cost low.
In addition, we have hand-picked tens of thousands of additional SNPs of particular interest from the scientific literature and added their corresponding probes to the DNA chip. As a result, we can provide you personal genetic information available only through 23andMe.
I don't have any experience with 23andme (though I seem to recall them having some financial difficulties), but the price was low enough for me to order a test.
An article by Steven Pinker discussing his experience getting tested can be found here. This has also been linked on Hacker News.
5 years may or may not be too far out. In November 2007, after all, it was a cool $1000: http://www.nytimes.com/2007/11/17/us/17dna.html
AFAIC, the current $429 price was put in place in September 2009.
So it dropped >1/2 in <2 years, and from 400 to 100 is just 2 halvings, or ~4 years.
I expect that it will be technically feasible to offer <$100 SNP analysis on 23andMe's current scale (>=550k SNPs), but the determinant will be business factors - what's profit-maximizing? Do they have the resources to scale to demand at <$100? etc.
I think they will (lots of people and equipment being liquidated in the biotech sector will help them), and have made a prediction for during 2014: http://predictionbook.com/predictions/1677
Update: sometime in the past 3 or 4 weeks, 23andMe dropped its price to $259.
2011 has just arrived, and we only need one more halving or a sale to match this prediction! 5 years seems likely to have been surprisingly pessimistic.