The Mail transition has been a no-brainer. But the one problem with iCloud that persists is it's behavior with Exchange servers. Before moving to Lion and iCloud, I could send and respond to calendar invitations via iCal. Now, though I can still send them, I can't respond to those I receive. When I click to respond, I get an error message saying no can do and asking me if I want to go offline. If I click yes, the calendar notification sticks, If I click no, it vanishes. I've posted a/b this on the Apple discussion boards, as has a lot of other users. It's been collective head-scratching and a lot of silly folk-medicine type "remedies". But not true joy.
As for the end of iDisk, I'll just start using my Network Solutions hosting package for that.