There are a few threads on this subject but I'll reply here since it probably primarily affects those that travel in/through the UAE.

The ban has been lifted according to The Register,

"The United Arab Emirates has cancelled the planned ban on RIM's BlackBerry service, saying that it no longer represents a threat to national security, but not explaining why."

http://www.theregister.co.uk/2010/10/08/rim_uae/