It's probably safe to say that Polly will have something to do with the plot, but I can't imagine her being the villain anymore. The idea of Moira not recognising her voice because she hasn't seen (or heard) her in a long time makes sense, but speaking of the voice, it sounds way too old for a woman who could now be in her mid-twenties at most. (Then again, American McGee's Alice, who is supposed to be 18 or 19, was voiced by some grandma too, so who knows...)
As for Steve, it would be nice to see what happened to him, and Claire repeating a line he said to her in Code Veronica might actually be a hint, but I'll continue believing that the fingers on Wesker's photo belong to the female villain until I'm proven wrong. And no, saying that they apparently look male doesn't prove me wrong.
Just a question, without implying anything in particular: Does anyone know what Lisa Trevor's hair colour is/was? For some reason she's always blonde in my imagination, but I'm not sure.