I love wordpress and using it for a CMS. I never thought it needed to be simpler, I always thought that was one thing they did really well... But maybe thats just because I've been using it for many years now.
Blogging with a simpler interface...isn't that Tumblr? Is it late for Wordpress to think about going in this direction? (I read the article but didn't watch the 20-minute video.)
It might be late but WP has a massive, engaged user base. They should build what best fits the needs of their audience not what might keep users from leaving for Tumblr.