I wonder if we'll meet Lita now. I suspect that she keeps at least her most important employees under mental control (what with Lesley and Zoe replacing "God" with "Lita" in their speech). Vampires also would double as renewable food sources: They don't die upon being drained, and they go back to full health after drinking some blood. Lita could buy blood to feed her pet vampires and use their lifeforce in turn to feed herself.
Also, will Lita be OK with Katie, Leonard and Suki trying to go back to their own time? If they success they could rewrite the timeline, erasing her empire. Zoe will probably try to keep Suki around too...I foresee a battle, or at least an attempt to mind-control them.