Just to pick you up on one thing, we have sequenced thousands upon thousands of genomes since the human genome project finished.
For example there is the 1000 genomes project [1], and a project I am working on is sequencing about 100 ovarian cancer tumor / normal pairs. Most of this sequencing is complete, its the bioinformatics that takes the time.
GWAS studies (studies of correlation between disease and common SNP's) have not told us much that is actionable, but have provided us with "low hanging fruit" for further study, which is valuable.
Its very early ways, but genomics will completely change the diagnosis and treatment of cancer over the next 10 years.