Luckily a huge amount of mapgen samples will be provided today. We gonna see first hand what the mapgen is capable of and what kind of games it provides - If it can reliably create reasonable maps.
That said, I dont think the quality assasment of current hand made ladder maps can be directly transfered to mapgen maps. The will likely never reach the aesthetic level of hand made maps - especially if you look at the astounding progress in the last maps made by Jip, Svenni, biass and other map creators.
The huge advantage of mapgen maps is, well, they are generated and no one has seen the map before. In short, its their novelty. And novelty is a quality of its own. Mapgen trains a player to adapt, to asses what a map has to offer, to think what might be good and what not so much. Hand made maps with established meta simply cannot provide that feature.
My point is, even if mapgen maps lack in comparision to hand made maps in some regards (which they do), they bring some new quality into the game which current ladder maps simply cannot provide.
Therefore I would love to see mapgen maps in ladder to some extend.