Same issue for me-- I couldn't readily determine whether this was an open source project, like MediaWiki, or a hosted service that I'm going to pay to use. A lot of the corporate and pricing info I look for was under a different URL, EdGenius, which adds to the confusion.

The signup button should lead to a page explaining exactly what I'm signing up for, rather than the existing lightbox, which has an unattractive little form offering no details.

I like the overall presentation feel on the homepage; you just need to provide more direction for the new user.

Same here. Stared at the big wall of text. Not quite sure what I was supposed to do--both options (sign-up / download) turned me off.

good point, I changed it. Now it looks a little ugly, will do improvement later. But anyway, people won't miss that 2 buttons:) Thanks.

You need to make the sign up button have a link cursor. I almost didnt click on it because I thought it was only an image.