In an age where every Gok Wan, Louis Spence and Stephen K. Amos is not a novelty, and we are no longer shocked by Sue Perkins, Jane Lynch and Wanda Sykes (I couldn't find any more lesbian celebrities who are British!) I see more media attention on bisexuals for being bisexual. Not a lot, but they have replaced articles about gays being gay.
This post was inspired by an article in the Sunday Times where I read the revelation (to me, that is) that D H Lawrence was bisexual.
Some celebrities who are out bisexuals include
Carol Ann Duffy
Craig Revel Horwood
Drea de Matteo
And those only rumoured to be (or may be those who have experimented/be bicurious) include
Kathy Najimy (look her up, you'll recognise her)
Florence Welch (Florence and the Machine)
Hans Christian Anderson
Sammy Davis Jr
Robert Downey Jr