The more astute forumers have been saying this for a long time. That gk104 was not the flagship, as should be obvious not only from the various leaks and GTX670Ti renaming cover-up, but by the design and lack of DP and memory bandwidth compared to the previous flagships.
I guess NV took a page out of AMD's playbook when it comes to gaming GPUs, but executed better: go small die, high efficiency, lose the HPC stuff, and put two on one PCB to combat the other side's monolithic GPU. Just like AMD did with HD4870/HD4870x2 vs. GTX280, and HD5870/HD5970 vs GTX480, and HD6970/HD6990 vs. GTX580.
The difference is that NV's top gaming GPU actually edges out AMD's top gaming GPU, i.e., 680>7970, whereas 4870<280, 5870<480, 6970<580.
The 480>5870 & the 580>6970 by all benchies I have seen!
When 28nm process becomes more mature, NV can probably get much better yields on massive GK110 GPUs, so it makes sense to wait. AMD is not really a threat in HPC and pro graphics so NV can afford to wait.
And I guess there is a market for HPC that does NOT require DP, hence the K10 launch.