I am afraid that the switch to iCloud will make life very complicated, particularly for Snow Leopard users like myself. I am also afraid that Apple will make life generally more complicated.
So I am wondering if I can theoretically switch to another provide for synced email configurations, address book data and calendars.
I don't mind paying for those services, I just need my address book, emails and calendars to be the same between my devices, ideally between Mac OS X and iOS and everything else (Linux, Windows, Solaris etc.).