The reason for this is that commenting was never members only to begin with. Anyone with a Livejournal account can comment on posts, and the only thing that has been members only has been the ability to submit posts, which then have to be approved anyway. So it wasn't really serving any purpose other than to give us mods more work that we don't really need (we get several requests a day, usually). So we talked it over and decided to just open up memberships.
Nothing will really be different other than not having to wait. Hopefully it'll be more convenient all around this way!