I don't like it, but I think it has potential.
At the moment, it's possible to know who will win a T20 match after the first 10 overs. With the breaks in momentum there are more opportunities for the game to take a different direction, which is a good thing.
That said, I think the break should be 5 minutes or less and that perhaps some of Ray Jennings' suggestions should be taken onboard - like interviews with players about how the match is going, that sort of thing. Gotta entertain the masses.