I just tried installing the file that was from the link. It looks like it is the Entune 2.1 Update, and not for the Maps.The latest update was uploaded here http://www.sendspace.com/file/00cwar but beware if you dont read it properly you will also download a malware/spyware.
MAKE SURE YOU DOWNLOAD THE 266MB ENTUNE.ZIP AND NOT THE 275K ENTUNE.ZIP.EXE
Just remove the check on the box under the download link
When I put the USB with the files into my car it said that it was a software update, but that I wasn't allowed to downgrade my Entune and go from 2.2.0 to 2.1.0.