I've been in touch with Lillian. She says that so far (as of Tuesday) Lui is OK. There are still a lot of soldiers in the area, so that's a concern, and many IDPs are arriving in Lui from Juba. Lillian had gone to bring the children back to Lui for Christmas, but because the fighting broke out in Juba, she and they are got stuck in Kampala with Bishop Stephen still in Lui.
I have a 20-page pdf on the situation in South Sudan as of 1/2/14 published for Congress by the Congressional Research Service. It's quite comprehensive and reasonably unbiased, and it gives more perspective on what the US government is doing and has done than we usually get from the media. I don't think it's available online (yet), but it's freely shareable; if anyone wants to read it, let me know and I'll email it to you.
My favorite bit of irony about the current crisis is that Sudan has said it's prepared to receive refugees fleeing the conflict in South Sudan.