Wow, I'm seriously glad to know this is a widespread problem. I've had issues since I took delivery of my 09 xB last November. Both lights had bad clusters... some of the LED's in the brake cluster were brighter or dimmer than others.
Unfortunately my dealership gave me a serious runaround, saying that they still technically work so they aren't a warranty-covered repair. After a ton of arguing, they replaced just ONE of the lights. The new one is perfect, all the LED's have uniform brightness. Unfortunately, the second one stopped lighting entirely a couple of days ago. I'm going to my dealership today for my 20k service and they damn well better order a light for me.
I do have a question if anyone else ends up reading this thread.. is it possible to replace the clear plastic covers of the TYC lights? The light the dealership replaced a few months back functions perfectly but the plastic has a small hole in it, courtesy of my girlfriend's idiot brother. The replacement cost of the light is a hell of a lot more than I want to pay because of some broken plastic when the light works perfectly otherwise.