That's what I'm guessing it will be. I'd be willing to be that's its name is the Apple Slate. Which I really like. It sound modern, fresh, and sophisticated.
If their trademark lawyers have anything to say about it, it won't be "Apple Slate." "Slate" is almost certainly not entitled to a trademark when used to mark slate-shaped computers, so you'd end up with every competitor making eSlates and xSlates and plain ol' Dell Slates.