Mobo sizes and hole patterns

I've been working some more on my new case and finally got to designing the motherboard mounting fixture, but I've run into a problem. I am planning on using either a Hammer setup or whatever Intel has at the time, but because of that I don't have any hardware to base my design off of. Does anyone know whether the Hammer mobos will follow the ATX spec, or will they follow something else?

They would have to follow the ATX spec or there wouldn't be any cases out there for the new Hammers when they come out.

I would take the mobo tray out of an old case and use that as the template for the ATX mounting holes.