MapBox, builder of open source tools for map creation, has just won more than half a million dollars to focus it's development efforts on the OpenStreetMap project. This is a big win for the mapping community because this grant will further the development of the community at OpenStreetMap as well as strengthen the open source toolset that the MapBox team has been creating. This funding might also serve as a confidence boost for MapBox API consumers. I should note that a quick google-check shows that tenured mapping players such as ESRI are also participating in the development of open source mapping tools.
If this gets you in the mood for mapping mashups, check out the 270+ APIs in the mapping category. Sort them by mashup popularity and you'll notice some strong preferences in the developer community.