A lot of your copy focuses on how this is just the beginning, how important this site is to you, and how you want feedback, etc. That's great for someone who already cares, but most visitors to any site are going to be ambivalent until they know what they're getting out of it.

Put yourself in the shoes of someone who doesn't care about you at all. Explain the unique benefits that that person can access right now. Appeal to their selfishness. Focus specifically on things that Sparkmuse enables (right now) that cannot also be said about alternative sites, such as Hacker News. Trim everything else away.