Seems to me automattic is trying to control entire Wordpress ecosystem slowly but surely. First there was the spech about curated list of plugins then came the buy out of WPMU. There was always Jet pack which ties everything up with wordpress.com. WPMU plugins will surely go through this too.

Now Stream which ties in with Wordpress.com. Its a slow but very deliberate process. Not disparaging what wordpress is or what automattic is doing. Just the direction the entire process is heading to ....

Its becoming closer and closer to what Drupal is except there seems to be a definite control element here when you connect things to wordpress.com.