Just found Luna Park via a reference in The Rattle litmag blog. As Tim notes in the latter, NewPages is great, but its reviews are generally positive. It should also be noted that litmags pay to be listed on NewPages, so it makes sense that the litmag reviews would be generally positive. They do a good job of giving press to noteworthy issues from the piles that they receive every month.
Luna Park, on the other hand, seems to have no monetary relations with the litmags it reviews (although it does feature ads in the form of links on the right-hand side of the homepage), which (possibly) allows for a somewhat freer hand when it comes to noting where litmags fall short. That being said, it appears that most of the reviews are glowing, with the Rattle review as the exception.
Beyond that, though, Luna Park provides news about litmags, excerpts from recent litmags, and commentary from editors and participants in the world of small-press publishing.
My position is this: Any coverage of small-press/literary magazine publishing is a good thing. The website is well-designed and the content is varied so I've added it to my favorites.