not link jacking, it's putting a message before the redirect. You're still redirected to the original page. One way to think of it is a reverse twitter, instead of a message with a link, it's a link then a message.
It's unfortunate that you'd like to tell us what annoys you, rather than being constructively supportive. Hacker News is a community where hackers get together and support one another, being blunt about feedback is one. Talking about personal annoyances does not fit in to what this community is all about.
I'm thinking I'm misunderstanding you, but if you have any feedback, we'd love to hear it. If it just plain annoys you, that's fine as well. If you don't mean it personally, I won't take it that way.
Interstitial pages with ads on websites are annoying enough, but this is taking it to a new level. When I (and I'd suspect lots of others) click a link, I'd like to be taken directly to that resource.
In fact, a day or two back there was a story posted to HN that went to a kiw.is link. My gut reaction was, "WTF, where's the article. Oh there it is. Wait?! That was a 3rd party interstitial? Whoever submitted that link is a jerk and a half."
So I guess what it boils down to is that I believe anyone who knowingly inserts an interstitial that could otherwise be avoided is a jerk and a half. Though, that's probably your target market; new media douchers for lack of a better term.