rbuenger says: "it's even one reson more for deleting MacOS and switch maybe even to windows. I want a small, secure and fully controlable system."
I don't see much logic here. I'm with you, though, don't want this all integrated and inseparable. I like Apple's thoughts in bringing us _separate_ iCal, Mail, iSync etc. And I don't think Apple will move away from this strategy anytime soon. However: Even if they're integrated won't mean you have to use them.
And: You want a "small, secure and fully controlable system"? We all know this just doesn't exist. Well, you could use linux and remove basically everything and work on the command line. ;-) We're way beyond 'small' with Mac OS X. But it is the most secure system around (beaten maybe only by Mac OS 9) and is quite controllable, too.