All the site really has is a beta signup button and one screenshot. I personally don't want to give you any information (including my email) for something I barely understand or see.
But a "Show HN" to me should definitely include more than this, I believe. The audience for these threads isn't potential customers but fellow programmers, hackers and entrepreneurs.
I wonder what the community response to something like that might be. I know I'd personally appreciate a company taking the time to put it together, particularly if they tout the "hacking" aspects of the product or how it came about.
For example, instead of an email signup, Show HN is for the thing you email people about once it's ready; instead of a fundraiser, Show HN is for what you build with the funds you raise; and so on.