Can say 2 Macs use iCloud to sync things
Can 2 Macs, say a desktop and a portable, use iCloud to keep things in sync like it ccan do with IOS devices.
iMac, Mac OS X (10.7.2), iPhone 4, iPad, VMWare with Windows 7
Yes, that's exactly what iCloud is for.
Contacts, Calendars, Bookmarks, Notes, Reminders, Tasks, etc. will all sync between multiple Macs that are setup to use the same iCloud account.