Paradigm shift. Post->Create, View->Search.
I think part of the YT problem is one of perception that reminds of the early days of Gmail. Remember when you 'put' messages in 'folders'? That's what people think of when they post. Instead you have 'Content' that is created that has certain attributes.
When you have content with attributes you can use search to surface it, rank it, and filter it.
So my minor suggestion for Youtube comments is to add a really simple thing: Add _Searching for Comments..._ to the loading indicator.
#googplus