With the Dow Jones cash just dipping below 15,000 it was only logical that the market would break. First up: CBOE declares self-help against AMEX, which is currently "out of NBBO and unavailable for linkage".
Update: all trades between 9:30 and 9:41 Eastern being reviewed and may be cancelled. Ostensibly, the sales.
Update 2: With the DJIA now solidly back over 15,000 the market is unbroken. It may rebreak if the DJIA 15,000 hats come off again.