I noticed there are 7 co-ed teams, 3 all-women teams, and only 1 all-male team. I wonder why on earth they did that?!?
IMHO, the all-male teams from the first 4 seasons have been 100 times more interesting than the dating/married co-ed teams, who constantly bitch and moan (Flo and Zack? Tara and Will? And now Allison and Donny? Ack!) The all-female teams, I have to be honest, have been boring as heck and fairly incompetent.
The male teams have been really funning and entertaining: think team guido, the dorky guy with glasses and his big bald friend, the clowns, the funny east-coast brothers, chip & reichen; etc. Also, all-male teams have won 3 of the first 4 TAR's. That shows they can be just as competitive and able to work together as any other combination.
Hopefully this wasn't done to weaken the overall field. You need some strong physical teams. Otherwise, let's just toss in 11 teams of 80-year-olds.