Just think of the lack of posts here and the lower number of users in the US as providing plenty of room for OSM use to grow in the future. As mentioned earlier, Google started charging for their API for high volume map use, ESRI has started a subscription service fee for ArcGIS Online, Bing has made it harder to use their imagery and maps, and it is only a matter of time before they all understand how much money they are losing by not charging for their services. It is all driven by money. OSM will become more popular among professional mappers when they have to start paying (or start paying more) for the alternatives. So, I see it is our responsibility to get the map in as great of shape as we can to ensure that those who explore with and hopefully migrate to OSM in the US are shocked at how great a resource they have overlooked.