You have to send a patch through Sony for certification as well. Basically though, Sony tends to focus more on the hardware side of things, however they can fail a title for simply not liking a part of the game design or aesthetics. They're certainly more nit picky about crap, whereas Microsoft generally goes by the book.
Patches and titles are also given more leeway if a studio has proven itself through numerous submitted and shipped titles. As an example, a new developer could have their submitted title/patch take 4 weeks to get through certification testing, but a more seasoned developer such as EA/Activision could take only one week.
