I am hearing, but can not see any information that there was an update pushed out for Mac users (likely a result of the crash issues upon startup with Firefox 9.0 release) earlier today. Though checking the Mozilla site and FTP site, the latest I am seeing for Mac (and for Windows and Linux) is 9.0.0 release from yesterday. Any Mac users on Firefox 9.0.0 (or even 8.0.1), could y’all go to Help > About Firefox and see if it offers you an update to 9.0.1 build.
Update (2:10 PST): Looks like it scheduled for public release later today as is showing when I looked on a different FTP server as Firefox 9.0.1-candidates. More info to come later tonight or tomorrow.
Firefox 9.0.1 is now auto-updating for the Mac.