As an example of what is possible from the open mapping interfaces, take a look at the iPhone app Skobbler. It provides spoken turn-by-turn directions (unlike Google's iPhone app) for free (unlike most turn-by-turn apps for the iPhone).
Not all is rosy with the mapping world, though. One of the weakest links is the GPS satellite network itself. There are a number of GPS jammers (illegal in US and many other countries), which are now commonly available at numerous online electronics stores for $250 or less. The issue is two-fold: GPS signals are easy to block, given that the satellites don't put out much power to begin with. And the jamming sources are very hard to locate, also because they don't radiate much power to do their dirty work. One jammer -- a trucker trying to get around paying tolls on the New Jersey Turnpike -- located near Newark Airport took months to track down. A trucker who was trying to get around paying tolls on the adjoining New Jersey Turnpike would interfere with a new system that the airport was trying to deploy.
To prevent this, the Defense Department has proposed a smartphone app to detect GPS jammers that people can use to report problems. Of course, then we all have to be persuaded to keep these apps running (and suffer the battery life consequences on our phones too).
What can you do?
If you have a retail business, or are looking at ways to better engage your customers, then you should certainly consider what these new breed of map providers have to offer. As a corporate developer, there are a number of steps you can take.
First, take a look at one of the open mapping sites and try your hand at putting together your own map to see how the process works. You can see my own primitive attempt to put together my own map here, using the Crowdmap interface. (Please don't laugh too hard: I just cobbled together a few things to show you what is possible with the site.) As you are constructing your own map, take note of how your data is input and what interfaces are required to post the map as part of your own Web site.
Second, spend some time using the location-aware social networks such as Foursquare and others to get a feel as to what is available, how your potential customers might be using these services, and whether you have a retail product or service that lends itself to promotion on these networks.