When he speaks normally he just sounds like a regular (and indeed very nice) guy like the radio interview I mentioned.
I guess he just does what he's told. It's a pretty cushy number really isn't it, he doesn't even go to the studios now, he has one at home he records the voiceovers from (except for live shows), so he's done very well for himself considering the nature of the job and the fact he would never in a million years be so lucky again!
Also as I said, they have toned it down a bit this year imo. He was much less involved than normal for example on the launch show I think.