Yes that is extremely important and I think Nokia can somehow work with Google to overcome this very important matter. I managed , after a lot of difficulty , to get hold of an Asha 501 , although strangely I already own almost the entire range of Lumias, odd isn't it ? Anyway I got hold of 501 and found that 501 has a very good youtube app for its size.
actually we got to think in terms of one side not wanting the other side to get to 10 %. Of course, if, and that is a very big if , Nokia gets to 50 % then it becomes Youtube disadvantage not to get onto Nokia train.