Thought of some more...
*More Duochromes, a more complete collection, rather than the hodge podge of ones they have now. I think they could release some really cool colors this way.
*More extensive base color range. They don't make most of their foundations (liquid) light enough for me. Also, I don't like how some products are NC/NW, and others have C, W, N, etc. Normalize this MAC, please! I'm sure darker shades would also be appreciated. Their mid range of colors seems good, just the ends of the spectrum need more work.
*Reformulate the nail polish. I love the colors, packaging, etc, but the formula could use some work IMO.