I agree it's easy to have a knee-jerk reaction, but we also have to consider the fact that people who don't like something are much more likely to speak out than people who are neutral or positive. Take into consideration how every major Facebook change has been met with a seemingly loud "boycott Facebook" petition.. on Facebook. We can't really over-police these things.
People wanting to censor dissent are a big problem on this site.
Slippery slope.
A delay between submission and unlocking comments stifles praise just as much as it stifles dissent.
But on the other hand, what other type of reaction is possible to a blog post that advertises a new feature that most people cannot try out yet and form measured reactions to?
You may be amazed, confused, euphoric, skeptical, doubtful, intrigued...
Doesn't that mean that we'd still get knee-jerk reactions from people who are latecomers to the article?
OK, then only allow someone to post if he has stayed in the article page for a while.