Here's a quote from the press release that I like:
"These changes are part of our strategy to improve operational reliability, grow capacity with demand, and enable us to achieve our long-term goal to improve margins and return on invested capital," said John Rainey, UAL's executive vice president and chief financial officer. "Customers tell us they prefer larger aircraft, and these fleet modifications will provide more opportunity for our customers to travel on the type of aircraft they prefer."
In other words, customers hate RJs. No kidding.
There's a 'new' investor update on the united website, including the fleet plan. As of now, there are no changes to the January fleet plan.