That's a great point @erikpinos about not being able to block spammy content. I think a simple solution would be to display "trending" on the main page. Sure, it's possible that spammy content will make trending - but most of the time it will be pretty decent. With a "new" view... you really have no idea what is going to pop up.

I also agree with you that it's great there are so many ways to interact with the platform! I'm a huge fan of @steepshot for that reason. I know way more people who use instagram than create blog or video content. I think Steepshot will be a big part of mass adoption.