Alex Levinson (cited in the above link) actually states that it has not been shown that Apple is collecting this data: https://alexlevinson.wordpress.com/2011/04/21/3-major-issues...
Apple's lead counsel Bruce Sewell says this is not the case as the identifier is randomized, and that Apple does collect anonymous location data from iPhones in an effort to improve its own database of cell tower and WiFi hotspot locations.
See: http://arstechnica.com/apple/news/2010/07/apple-responds-to-...
For example, here's one: http://www.eweek.com/c/a/Web-Services-Web-20-and-SOA/Apple-T...