I think there is a period of open enrollment at the beginning of each year for the exchanges. They won't be taking new enrollees year round.
It's kind of like our work insurance. A new hire is given the choice to sign up, but if they decline, but later change their mind they have to wait until the new period begins.
Just means they'll be going to the ER to be seen until the next enrollment period comes around, and considering the deductible vs. the cost of premiums for the low-end plans, it's probably the most sound course of action available, economically for sure and possibly even in terms of quality of care.
So yeah, Gina, that's what a very large percentage of the under-40 working crowd, who'll bear the harshest burden in the ACA scheme, are likely to do. This will of course completely screw up the risk pool since everyone who was uninsurable or otherwise a net taker before will beat down the doors to (They think) rob the wallets of the younger and more fit. I expect the whole thing to be drowning in a sea of red ink by the end of 2014.