Not an error - it has been mentioned everywhere that it is indeed coming out next week; however, that is 4.1 and not 4.2. The iPad doesn't support 4.1.
I'm pretty sure that's a typo. iOS 4.2 is going to be the patch that bridges iPad and iPhone, so they won't need separate updates anymore. 4.2 will bring all of the iOS 4.0 and 4.1 features to iPad.
SJ mentioned it won't be for the iPad; if they changed their minds or if he decided to lie then thats that. I just want freakin' multi-tasking already!