Running Mac OS Lion.
WD RAID Manager does work. However, WDDriveManagerStatusMenu does not work properly. You can run it and use it but it will shortly disappear from the menu bar.
In the console, I see two relevant entries related to WDDriveManagerStatusMenu:
11-08-04 9:20:42.683 AM WDDriveManagerStatusMenu: CPSGetFrontProcess(): This call is deprecated and should not be called anymore.
11-08-04 10:24:04.541 AM ReportCrash: Saved crash report for WDDriveManagerStatusMenu version 1.0.5 (1.0.5) to /Users/Me/Library/Logs/DiagnosticReports/WDDriveManagerStatusMenu_2011-08-04-102404_Super-Mac.crash
A crash report is generated but I can't upload attachments and I'm not sure if anybody from WD tech support even visits these boards.
Anyway, the status menu thing isn't really important to me but it does show the remaining free space as well as the temperature for each drive. I have two chained together via Firewire 800 to my iMac (27" 2011 model). Useful but not a deal breaker.
As a work around, I just created an alias to WD RAID Manager and copied the alias to my Applications folder. From there, I can access the application whenever I want.