This incident happened on Sunday, but it apparently wasn't until yesterday that avherald.com had the story and other news sources then followed up.

Nothing official, but from what I picked up on various forums, there was a complete failure of the green hydraulic system and the yellow system was shut down temporarily due to overheating. With only the blue system remaining, that caused a loss of yaw damper, among other problems, that resulted in a very uncomfortable 4 hours with many passengers vomiting from the yawing motions.

Jetblue A320 at Las Vegas on Jun 17th 2012, two hydraulic systems failed

JetBlue Airbus's mechanical meltdown sends it 'careering wildly through the skies' for FOUR hours

It's surprising that it took so long for this to make news, considering that there was a Daily News columnist on the flight and many others were tweeting.