A few more thing, take this as an example:
http://www.apple.com/iphone/features/
(not an Apple fan, but they usually get this stuff right; this page is not perfect, but not bad).
A few things:
* Notice the background color is darker than the content; this is to emphasize the actual content of the page. I would make the background color a bit darker.
* You probably don't have as many "categories" so I would put everything in one page.
* Notice the attraction points. Close your eyes for 5 second then open then. What do you notice the first second? This is where people will look first. You need to have the important stuff there or near it. The attraction points are usually images.
* Make a video or what your application does. People expect to be entertained, not to read. Once you capture their attention you can present more text / information. If you entertain somebody, either with a good video or nice eye candy, they will feel indebted to look more into your product. So the stages / levels should be 1: wow them, 2: convince them, 3: educate them
* Pay attention to details in your website and also your product. If your presentation page is good, people will at least give your application a fair shot. Their first impression is your site not the first time they use your application; that's way later.
For more tips:
http://www.dnrtv.com/default.aspx?showNum=112 and
http://www.dnrtv.com/default.aspx?showNum=123
Good luck.