The first interview was with the dept. lead and one dept. manager. They asked about my skills with Excel, experience I had in research, demonstrated ability to learn new software, if i was comfortable on the phone, how i managed stress, demonstrated ability to multi-task. The bulk of it was they describing the position and the role of the department within the company to me, asking if i thought i was interested, what i would or wouldn't like about it. Also asking the regular questions: what do you know about our company, what interests you about this position, why do you want to leave your current position.
The second interview was a panel interview of the rest of the department (10-ish analysts, 1 manager). This was supposedly to determine if I was a good fit "with the rest of the team." By far the creepiest interview I'd ever had. I didn't rush sororities in college, but from what i heard, i'd guess it was something like this interview. It seemed to have the undertones of "do you REALLY think you're good enough to be one of US?" They seemed like nice enough people, but to a point, it seemed as though they were trying to sell me too much on their "team/unity/sisterhood." They asked about strengths and weaknesses, what my goals were, what i thought the position did, what the work would entail, etc.
I interviewed with three departments with T-Mobile (receiving two offers), every department seems eager to "sell themselves" on why they specifically (their department) are a great place to work. Largely they seem to be 'culture' interviews. I accepted an offer with a different department, but felt generally this one was more likely to be repeated or encountered by others.