By registering, you can secure a username for the comments section, so no one can pose as you. There will probably(not) be additional features down the road as well.
Your email address will never be shared and will only be used for what you give permission. Your password is irreversibly encrypted with SHA-1, which is no substitute for scrypt and I should be ashamed. In other words if you trust your password hash with me, make sure it's a long, complex password because otherwise if my database is compromised SHA-1 hashes aren't too hard to brute-force. This is what I mean when I say there are detriments to registering.
Really though I don't care if you register or not. I dislike the blogs that demand an email address to post a comment (I always put firstname.lastname@example.org), and allow just anyone to piggy-back on your site with URL linkbacks (though it's something to be taken advantage of), and then to top it off want a captcha. Well, with mine, passers-by need only supply a display name (default Anonymous), their comment, and pass a simple captcha test. If you register, you only need to enter your comment, with a few optional checkboxes such as post anonymously and other features as they come, and no captcha.