**OpenStreetMap is not an aerial imagery tracing project.**
Aerial imagery is a great supporting element for OpenStreetMap mapping, but it is not our prime source of information. Traditionally, and long before we had any aerial imagery available, we have always been surveying with GPS devices. Given that even with the best aerial imagery, you will still have to visit a place yourself to map it properly, the absence of such imagery does not mean that "we can't put new info in".
in". (Not all mappers in OSM agree with this statement. For some areas, aerial imagery may indeed be the prime source of information.)
Also, there isn't one fixed source of aerial imagery for OSM; depending on the editor you use (and depending on the area you are looking at), different sources may be available. Some editors even support pulling aerial imagery from any WMS service.
But the main criteria for selecting aerial imagery for OSM use is not its technical availability or its currency, but its license or usage policy. **We Care has to be taken when selecting aerial imageray for tracing, for example we do not currently have permission from either Google or Mapquest to trace their imagery. Tracing from Bing or Mapquest** (or Google for that matter) **to use their aerial imagery for tracing.** Data traced from such imagery has to be treated as a copyright infringement, and removed.
imagery is now allowed and supported by all major editors.
We're always on the lookout for good additional sources of aerial imagery, so if you have connections to someone who owns the rights to good and current imagery, and is willing to allow OSM to trace from it, then discuss that on the mailing lists and we'll find a way to incorporate these images in our editors.
There's a [Wiki page][1] about potential sources of imagery.
[1]: http://wiki.openstreetmap.org/wiki/WMS_sources