As mentioned in the article... this does typically happen during the gap of time when CentOS is trying to put out new releases (and now 3 with 6.0, 5.6, and 4.9) out so this is nothing new.
I wish the article had covered how well the other RHEL clones are doing.
Scientific Linux - SL has released several betas and a RC for 6... so it is close but still not done. I haven't heard a peep about 5.6 yet... nor 4.9... but I'm not very attuned to their community.
Oracle - This commercial clone of RHEL/CentOS only released 6 a little over a week ago. I haven't heard anything about 5.6 or 4.9. Hmmm, does Oracle even have a 4 series? I'm not sure.
To clarify about 4.9, Red Hat didn't release refreshed .iso images... just packages. I'm not sure how each of the clone makers are going to handle 4.9. .isos or just packages?
Any any event, I think criticism of CentOS isn't really called for when they seem to be pulling their weight relative to the others. That isn't to say that I think this LWN article was critical (mainly informative) but I don't really agree with DAG or others who might feel otherwise. The CentOS developers are clearly aware of their issues and aren't trying to mislead anyone.
The advice goes... if you need updates faster than the community project can provide them and you can't build them yourself, you should probably buy one or more RHN entitlements.
At least CentOS is distinguishing between critical updates and less important ones as I think they should. I'm not trying to wave my hands and say security updates aren't important... because they certainly are. How have all of the other, non-clone distros, faired in updating the issues that also affect them? I'd chance a guess and say that almost all of them are doing better than many of the commercial OS vendors.