Mine froze seconds after installing the update. Then froze on restart and then finally got 3 flashing RROD on restart.
Called Xbox customer support who say its merely a coincidence and that I have to pay for a repair. The joke is they say the repair is deleting and reinstalling the update... which they claim is in no way responsible. Appalling customer service!!
There's a thread on the support forums with people with similar issues:
I also found facebook page on this googling today for people to report this. MS needs to admit its there mistake, do the right thing and honour the repairs:
Suggest everyone who's had this posts on both to get their voice heard