Does Zulu work with MobileMe and/or iCloud?
It works "along side" MobileMe because Zulu and MobileMe kind of do the same thing.
MobileMe is an iCal Server (it stores your calendar data). And Zulu makes FileMaker an iCal Server as well (technically, both are CalDAV servers). So, the things you do with MobileMe, you do with FileMaker:
Add the FileMaker calendar to your iPhone and you'll see what I mean.
Now, MobileMe's doesn't support showing other iCal Servers (other CalDAV accounts) in it's web interface, which is kind of a bummer if that is the only way you interact with your calendars. But if you interact with your MobileMe calendar in iCal or on your iPhone, your FileMaker calendars will show up along side them.