Can I fix things so Archive Utility doesn't hang on all zip files?
It's related to the Apple Events bug in 10.8.2 that also makes revealing files in Finder stop working.

As a workaround, you can terminate the appleeventsd process with sudo killall appleeventsd sudo killall -KILL appleeventsd. (Without -KILL the process is sent a TERM signal and many processes stop responding as @myhd described.)