I haven't read the article yet, but one of Twitter's biggest problems is that they listen to their whiny users too much. Facebook will roll out updates that change large parts of the interface to great protest, and then see increased engagement and growth because they are actually improvements. Twitter needs to get past the musings of backseat designers in the media and their crankiest users and start improving their product.

EDIT: Just read the article, and as I thought, it looks like a promising experiment. They are removing direct user control over who will be notified by replies in favor of handling it automatically. This also cleans up the interface a bit by removing long chains of usernames from the front of every reply. I can't say if it's ultimately going to stick, but it's a step in the right direction.