I'm currently using ArcGIS Desktop 10.0 and saw that complimentary use of Bing Maps will be discontinued in February 2013 and that a key needs to be obtained directly from Microsoft in order to further use Bing Maps with ArcGIS.
Does anyone know how to go about obtaining a key from Microsoft or how much it costs?...or is there an annual fee?
You'll want to create an Windows Live ID first. Once you do that, you'll be able to create a key. It's free, unless you're using more than 125,000 transactions within a 12 month period. Here's some more information that may be useful on transaction information and usage limits.
@jonathan, do you know if this affects ArcGIS online and whether each person in an organization would need a windows account to access maps created for ArcGIS Online access using mobile applications as well?
In the next update of the website, we will allow the administrator of an organization to specify a Bing key that will be used by all members of the organization.