They're saying this afternoon is the expectation. I imagine it'll be after W has his apparently "traditional" (as FNC put it) off-the-record chat with the muckity mucks of journalism: Timmie, Brit, Chris Wallace et al. They're having this casual lunch right now, apparently, where W listens to their thoughts about the issues and shares a bit of what he'll be saying tonight.
Wouldn't you love to be have a listening device on Barney for that gathering? Wonder if Timmie will keep all the secrets ;).