I use two Skype accounts: one for business and another for private contacts.
When I'm online with Skype I can get incoming calls only for one of my accounts and thus I will miss all incoming calls for another account.
It would be nice to get all incoming calls for both accounts (similar to when you receive messages at several e-mail accounts). Or at least to register all incoming calls even if you are offline at the Skype account they come to.