I have never seen that Obamacare has received funds for implementation. I do remember talk about using Medicare funds for Obamacare.
If you can find anything saying it's been funded in anyway please post a link. I can't find anything.
I know without researching a thing that the infrastructure has been under construction for four years and the exchanges are ready to open in two days. During that time the average citizen has been shielded from any direct affect of the law.
The equation is simple; a delay gives the administration one more year to build infrastructure while the people are shielded from its pain for one more year.