Fact is, one guy cloned what was a closed platform (that had been openly announced and displayed) based on the idea and screenshots alone in about 11 hours (based on the HN submission interval).
If someone can do that--and does--you really haven't invented or created anything (substantive).
This just leaves the issue of whether the design and the assets (CSS, images, etc) are substantive and have been used without permission. Based on other comments, there seems to be no issue of asset "theft".
So does the minimalist design copy warrant outrage? Honestly, no. Someone has basically invented what amounts to a Wordpress theme.
If dcurtis can create a scalable, reliable platform for hosting it then great. It worked well enough for Wordpress.
Exclusivity and invite-only are time-honoured ways of scaling controllably and--let's be honest--creating hype and desire but if you're not ready for the copycats and it takes the copycats so little time that their HN submission makes it to the front page while yours is still there... that's your problem.