From the podcast:
During the nuclear explosion that destroys the Cylon ship, something happens as Kendra and the hybrid are killed. On resurrection ships we see, in glass cases, a new line of Cylon being molded, created and this new model of Cylon is...Kendra. She knows everything about them (the Cylons) and about us. In Season 4 they (those on board Pegasus, Galactica, etc) would have to deal with the character in a different way as she may now be the enemy.
My two cents:
I'm torn on the thought of Kendra being the final Cylon model. I do think Kendra was a very interesting character and one I hated to see go so soon. But I thought they were holding back the identity of the final Cylon because it was going to be the shocking reveal of a character we are deeply invested in. Though it seemed clear that at the time of the recording of the podcast they still didn't know who the final Cylon would be. Which would be in keeping with the debate last season as to who the four they would reveal as Cylons would be. If Kendra is the final Cylon then it would mean Lee, Kara, Laura, and Adama are not and I think I might prefer that scenario.