First I would like to say I love haiku. You guys are doing an amazing job. I can almost see myself using it as my primary os on my home pc, even though its still in alpha!
Anyway one area that I feel is lacking would be Webpositive. Blocking js should be a primary concern with any respectable browser. It would be awesome to see some form of per domain whitelisting (like noscript), but even just having an option in the settings for completely disabling scripts would be better than nothing.