hm not so sure about that.. i think a great deal will actually be the same, they've mentioned running the full clr so there is unlikely to be any silverlight left..
Given how much windows 8 is likely going to be in wp8, it seems the winRT core libraries are going to be very likely.. and after all, the xaml implementation in win8 is actually native code..
But so then why didnt they mention winRT? who knows.. microsoft is known for their poor marketing strategies and event that create more confusion that awnsers. they might have considered this event to have a non technical audience, or the actual details are not really locked down..
it seems they did everything to indicate winRT except actually saying it..