I looked at your pictures, and wow your yorkie is soo cute !
I know much about this breed and the standard, i don't think his ears are big, they are just in the normal size
If you check my FlickR,
Flickr: I Am The Sun's Photostream ,then you can see pictures of my boy.
My boys ears are perfect (except they are floopy!)
Everything with him is 100% in standard, EXCEPT his floopy ears who wouldnt go up, his overbite and big size (he's 6 kg.)