JOSM is right now the most popular editor in OSM. It's desktop software and very powerful. JOSM is very much a power user tool where iD is aiming for a great experience for beginners and casual users.
It's fully functional, and you can switch over to the live OpenStreetMap database by clicking 'dev' in the lower right. Loading and saving data happens via an XHR request to the OpenStreetMap API hosted on http://www.openstreetmap.org. The API supports CORS, making direct cross-origin connections possible.
This article completely misses two important points. The first is this: Google is not just in the webmap and geocoding business, but is pursuing the goal of being the go-to warehouse of world wide geo data, with Terms of Services [1] that completely tie the user to Google's tools. The second is that the OpenStreetMap eco system can and is competing against Google's tool chain, declaring defeat citing sea containers flies in the face of people who are working hard every day to make "open" the prevalent way we do maps.
For a little background on Google Map Maker look at how Google is starting to run a more aggressive mapping campaign by announcing a partnership for sourcing geo data [2] with the World Bank, a community site [3] that looks a lot hotter than osm.org and Mapping parties all over the world [4].
http://josm.openstreetmap.de/