If you are still using ArcGIS Online tiled services in WGS84, that other shoe you’ve been waiting for has finally dropped. The inexorable march of Web Mercator will apparently roll over ArcGIS Online around spring of 2012. From the e-mail that Esri sent today:
This e-mail is to inform you that we are no longer updating GCS WGS84 services and will be retiring them as early as spring 2012. Before the WGS84 services are no longer available, we want to give you ample opportunity to migrate to the newer web Mercator services, if you haven?t done so already.
Esri has been telegraphing this one for a while so there is no room for shock or outrage. If you are still using the WGS84 tiles in your application, you’ll just have to get past your preference for seeing Greenland in Gumbyvision.