Their call centers are highly regulated and every call is recorded using NICE systems (NICE is the brand, that wasn't meant as emphasis)...
NICE is...well...nice...it offers a lot of analysis options for a call center manager. Depending on which call center you spoke with, it would reflect which system you were recorded and analyzed on.
Anyhow, the final point is, it's probably just part of their script, and as maryszhi said, it's to make sure if you had any final questions, etc, they were covered.
I've noticed, between booking in 2010 vs the booking I did a few weeks ago for my trip next year, the CSRs are on average more knowledgable about park activities and are more conversational. I applaud Disney for taking this move. In 2010, it was all very transactional, and frankly, by the time I was checked into CBR for my first trip back in nearly a decade, and the first one I planned on my own with no parental involvement, I was concerned that Disney had oversold itself on service (I had a bad Magical Express ride and Check In experience that year).
Of course, if you look at my signature, that impression didn't last long. But, I enjoyed the booking for 2012 and 2013 the most, and having run call centers before, I smell a policy/culture change there. So, kudos.