The great thing is Droid depends on a gmail address to operate the phone and sync up, etc. Apple's Address Book has the option to sync with Google & Yahoo, so simply go into preferences and check the box, enter your email and password for gmail, and it will sync all of your contacts. THEN when you get your Droid on Friday, simply select the option to sync with Google contacts.BAM!!! All of your contacts are now on your phone and can be synced again and again anytime you need to change something. The calendar is a little more tricky, but it can be done. All directions can be found here and whatever you enter in Google Calendar transfers to iCal and vice versa.
Get Started with CalDAV - Google Calendar Help
Hope this helps anyone questioning how to make this work on a Mac.
Also, I created an entirely new gmail address so that way I don't have a bunch of junk mail/forwards being sent to my Droid's email when I get it.