I recently listened to tennis on the Radio.. I don't remember what the event was, but it was when Federer and Nadal had their epic match, and they had these two British guys doing the pxp, and it was surprisingly interesting. Don't forget, when you watch Tennis on television, there isn't really much pxp. They mainly talk during the breaks and in between serves, but not when they're actually playing, except maybe to comment on something, not say what is going on.
Anyways they'd say like, "Nadal backhands to the left side of Federer, Federer lobs it back to Nadal, etc etc" but it was amusing because they were so enthusiastic and they would get higher and higher as the rally went on, and I honestly felt that if they had a 12+ hit rally that one of them would pass out from lack of oxygen.
I did find it to be rather interesting though. As I said, we're basically USED to having commentators give pxp on radio and television, but imagine watching a game where there is NO commentary when the main action goes on..