Exactly but the ban starts on January 1, 2014. You can safely start COBRA now, since with the recent election there's no chance the law will be overturned before then, and little chance within the next four years. After that it'll be pretty well entrenched.
It's interesting to consider that at this point, people are going to start planning things like COBRA coverage on the assumption that they'll be able to automatically obtain private coverage in 2014; this bolsters the case against any partial repeal of guaranteed issue, as it'll screw lots of people over if they do it.
Here's a timeline of Affordable Care Act provisions: http://www.healthcare.gov/law/timeline/
Note that the law not only ensures you can get insurance, it prohibits insurers from charging higher premiums for people with preexisting conditions.