There was an immemdiate drop in prices when ddm2 was announced, for some minis. There was another dip as ddm2 was executed early on, but it was smaller. I believe there has been one more small dip.
But, for the most part, DDM prices are driven by roleplayers (with a few exceptions). This licensing may keep some prices from dropping, but I don't know. Actually, I think it likely that the prices of goblins, orcs, and kobolds may go up, slightly. There will be less minis per box, at a higher price. That implies to me that prices per mini will need to go up, on the secondary market. I also think some secondary market re-sellers may bite the dust, but I'm not sure. It's my prediction that prices will stablize toward the more expensive end of on-line sellers, and that we'll lose the super great deals at the low end.
There have been less collections sold off than many expected, since the announcement. I think that shows that those with large collections (like me), are either only RPG/collectors, or if also DDM players also colletors/DMs (with some exceptions).