The problem on the IAH-EWR flight apparently was an indicator light in the cockpit. At least that was my interpretation of what the captain said when he first announced the problem after pulling back from the gate.
(Related humor:
http://www.youtube.com/watch?v=KMhp2ShPVQw)
The previous leg out of SFO was quite uneventful, but yes, we arrived in EWR about 3 hours late.
I enjoyed my first trip on the 787. Apparently this one (#3906) was the second of the 787 deliveries. I think we have a winner. Much has already been said about this plane here. I was surprised how long it takes the windows to darken/lighten. Economy seats were reported here to be much narrower, so I was expecting a crummy seat, but to be honest, I couldn't really tell if they were narrower or not. I wouldn't have any trouble surviving a long-distance trip in E+. The flexing of the wings is quite amazing. Upon final approach it seems the tips of the wings are higher than the top of the fuselage.
Lots of people were taking pictures of the new plane, including the ground crew at IAH and EWR who had out their cellphone cameras.
All in all a very cool experience, even with the delay.