I see where your coming from. The deep Micro ATX board would force me to make sure - this board would fit into a solid case. An actual SSF is coming from Lian Li and Dan based on the MicroATX. The case is not released yet, but it could be a possibility.According to ASRock it's "deep micro ATX", which I've never heard of before. After looking, it is taller than micro ATX by one slot width, so it won't fit in micro ATX cases.
Some good knowledge -