ArcGIS.com is a great online GIS tool. Earlier this year, Esri had to remove the Microsoft Bing basemaps that were previously available to users. All conspiracy theories aside, this was a huge blow to online data collection. The Bing imagery is crystal clear and while second to Google in overall coverage, In a few areas the quality is actually far superior. As well, Esri does not have a good imagery-plus-streetname basemap similar to Bing's hybrid map.
There is some attempt to explain all of this on Esri's online resource page, but it doesn't get into the "why". It's worthy to note here that you should keep your MXDs with Bing Maps already added. While you can no longer add Bing imagery to a new ArcMap document, You will be allowed to keep existing layers. Also, you will be able to use Bing Maps in the free ArcGIS Desktop Explorer, which leads me to thing it's a MS licensing issue and not a Us vs Them problem.
At at any rate. Bing Maps are great, and we all still want them on our maps. You can still do this by using a Microsoft Bing Maps Key. The video below explains how to do this in a short 4 minute tutorial.
