Finally things have settled between the two giants we now have the official windows phone you tube application,you can also upload from your gallery too which is an added bonus,this again is another step forward with windows phone and the application growth.
As you can see it works perfect on my nokia lumia 925 so go get it now.
Link here– http://www.windowsphone.com/en-us/store/app/youtube/dcbb1ac6-a89a-df11-a490-00237de2db9e
Enjoy.