CBC and Ghomeshi had been in discussions about this for a period of time and Ghomeshi agreed to take an indeterminate leave as a result. Something new must have come to the attention of CBC which resulted in the severing of the relationship between CBC and Ghomeshi.
The Toronto Star has been investigating the allegations since last summer, allegations by three women, actually four, three with abuse and one with harassment.
"Early last summer, the Star began looking into allegations by young women of sexual abuse by Ghomeshi over the past two years. The Star conducted detailed interviews with the women, talking to each woman several times. None of the women filed police complaints and none agreed to go on the record. The reasons given for not coming forward publicly include the fear that they would be sued or would be the object of Internet retaliation. (A woman who wrote an account of an encounter with a Canadian radio host believed to be Ghomeshi was subjected to vicious Internet attacks by online readers who said they were supporters of the host.)"
http://www.thestar.com/news/canada/2014/10/26/cbc_fires_jian_ghomeshi_over_sex_allegations.html