TXU is quite laid back and fun company to work for. Marketing department drives TXU Technical department specially Web Technology group. The interview had 2 rounds. First round was very basic, over phone, simple OOPS concept. I recommend Illustrated C# by Apress to be your key to go through second round. The second round was group/panel interview more technical about Sitecore, Page Life Cycle, Web Controls, some design pattern questions, WCF.