When i heard it I was quite surprised, but David Davies, the 1500m british swimmer, is gonna have a go at the first Open Water race at the Olympics! That is assuming he qualifies by finnishing top 10 in Seville, but seeing his performance at the 10km in South Africa, I think hes pretty much a dead cert to qualify.
http://news.bbc.co.uk/sport1/hi/olympics/swimming/7286154.stm

http://news.bbc.co.uk/sport1/hi/olympics/swimming/7309865.stm - News article on his recent Silver medal on the 1500m at the European Champs.