But that "tracking data" turned out to be just a local cache of cell tower locations that the phone had been near. It was not a record of the precise locations your phone had been and if someone wanted to track you it would only give accuracy to the roughly the nearest city.
There's a lot of data that's only in OpenStreetMap, as compared to the other big map data providers like Navteq. In addition to roads, OpenStreetMap has bicycle paths, pedestrian paths, hiking trails, and a host of other things that are not generally collected in other general-purpose road databases. At least one person on the OSM mailing lists has pointed to an area where he added some but not all of the hiking trails in an area and Apple is showing only the trails he added to OpenStreetMap. Even more conclusive, though, is that when you overlay the two on each other, such as at http://ivan.sanchezortega.es/leaflet-apple.php , there are quite a lot of places where the data matches exactly--not just "both have a road here", but "every point making up Apple's road lies exactly on top of a point making up OpenStreetMap's road".
In practice, OpenStreetMap is more up to date than Google for areas where locals know how to update it. That includes quite a lot of Europe (particularly Germany and England) and most metropolitan areas in the US. As more people learn about OpenStreetMap and begin using products that include OpenStreetMap data, that pool of up-to-date areas will grow. Basically, right now, there are areas where Google is better and areas where OpenStreetMap is better. (But where OSM is good, it's generally *very* good.) Also note that not only is Apple using really old OpenStreetMap data (the OSM database has more than doubled in size since April 2010), they're using US Census TIGER data in the US, which is often really, really bad.
Slashdotted. They're working on getting the site back up. The gist of it is that OpenStreetMap only really provides raw map data and building a useful product on top of that data, whether it's map tiles like Apple's photo app is using or turn-by-turn navigation like Skobbler, takes a fair bit of work. switch2osm.org takes you through the basics of putting the OSM data to work for you.