First off, I think you folkes already know everything that I'm fixin to say but I'm going to say it any way.
I'm going to say it because it is in my wheelhouse and I have experience with big (In my mind) application rollouts.
Healthcare.gov is, without a doubt, the most ambitious IT project ever undertaken. I mean just imagine, it touches...
IRS
HHS
Homeland Security
Social Security
Treasury
These systems were not developed within a single project...meaning, these systems are all dissimilar. That means that the federal data hub had to be coded specifically for each back end database. In a best case scenario that means that you had 6 teams working on the hub. One for each federal agency's database's and one for the hub itself.
Now consider that they are "working to fix" an active website. They shutdown the site from 1am to 5am or whatever every night, swapping out code.
They are swapping out code (and hardware) on the frontend website and the federal hub. It is unpossible to do an end to end security check on the new code before they turn the lights back on the next day...unpossible.
I would also take a moment to note that the one person that was in the position to sign off on the Healthcare.gov websites security, Tony Trenkle, failed to do so and either retired or was fired. Marylynn Tavenner [sic] signed off but she has exactly zero experience in security.
Another thing I'd like to mention is the current efforts, moving through the house and senate, to save the "if you like your plan you can keep it" bullshit.
I spent a number of years supporting the folkes that program NASCO.
Nasco is the mainframe system that Anthem relies on to maintain their business. It would take years for them to make the programming changes needed to revive their cancelled policy's.
So the policy's that have been cancelled are dead and gone. I understand that Cali is telling Insurance company's that they must stop cancelling plans that by law must be cancelled. That is not going to work..
So to end I am predicting that the whole thing is destined to collapse and die and one of the reasons will be a massive security breach probably reaching through the federal hub into the 5 fed agency's that must be wired in.
If you must participate in the exchange wait till the last moment, and even then wear your underwear backwards for good luck.