HN isn't broken. So please, don't try to fix it.
Right now there is no distraction anywhere. It's straight to the point: Here are your headlines. Read first post title, if you're interested read/open, else proceed to next headline. The meta info (points, comments,...) in lighter grey colour serves as element to visually separate the individual posts making them easier to parse.
Your design I find busier. Name of the poster and amount of comments are unimportant while parsing headlines (for me?) and thus are in the way. The light colour on #other is barely noticeable on my uncalibrated TN panel TFT and doesn't help at all. For individual post/how comments are displayed I'd say the same thing. Username/points are way to prominent vs. the actual comment itself (and the up/down vote arrows are still on the same spot :D instead of downvote to the right of the meta information)
Aside from that, your design only has different colours with a fugly orange "more" button at the bottom.
Neither your design nor the current would be more or less 'perfect' when I'd first see it but in hindsight I prefer the current one; I am better at parsing it than yours for the reasons stated above.
Rather than a new design, I think HN could more benefit from new (and optional) ways to order and present the posts and comments. I'd like to read comments in their chronological order, for example, to get a better feel of the progression of the conversation.