I don't really care for the atmosphere of these Fed/Davis cup type matches in general. But obviously the idea is to have some more playing options for tennis, as a team sport and crowd attraction.
But picture an NBA basketball game, how the crowd treats the opposing player at the free throw line. Can you imagine this in tennis -- jeering to distract while the 'opposing' player is serving? Really in these links it is to that point.
I see this behavior creeping into the Grand Slam events as well. I attended several days of the last US Open, and felt a little uncomfortable at some of the American players' matches. Nothing came close to these video links, but the crowds did get aggressively jingoistic at certain points. And the announcers and US tennis establishment seem to encourage it.
IT's just not my cup of tea, because tennis is at its heart a one-on-one sport. It can be very lonely out there not just playing against an opponent, but an entire stadium. j m o