Telenor has announced that they now can deliver Enterprise Voice in Office 365.
From this page: http://www.telenor.no/bedrift/office365/ we now can read that Enterprise Voice in Office 365 can be used. (Sorry that the page is in Norwegian)
But you need to be a Telenor Customer on telephony.
But the can't at present time offer an Office 365 Attendant like Competella or Trio. This still has to be OnPremise at present time.
There are also no Mobile Status information either, this has to be used OnPremise, but from what I have heard from Telenor, there will come more and more services for this Office365 later.