People will come to you for two things:
(a) Links, yes unfortunatley
(b) Real reviews
You need to mod submissions. You either narrow it to 'applications' or anything websites go. Based on the former I would not list any web sites selling Bollywood or templates.
Go for freemium, free rating and comments, but have some people who are professional to give a professional assessment and charge for tis perhaps on a 50/50 basis.
Building a community is hard work, but most of the times you need ten or twenty very active members to provide the catalyst for growth.
Ask the same question at http://www.cre8asiteforums.com/ also. Here we are all HN groupthinkers you may get some different angles (usability, SEO, community) from some really nice people.
Final question to you, would you pay for a review of launchly.com? If yes what would you consider value for money, if not why not!