(This is something that I wrote on kottke.org.)
Great idea, I love a good comment section and this seems a good way to manage it. They, and this text field, look nice too. I’d quite like a “Preview” option before posting.
Back when Twitter was less bad and more popular with people I know, I thought that only allowing people I followed to post comments on my blog might be one way to filter out spam, but that would have had its own drawbacks.
One of my favourite comment-enabled blogs is The Online Photographer. They’re a pleasant, knowledgable bunch and Mike Johnston reads and approves (or doesn’t) every comment, which keeps the spam out.
See on kottke.org.