Piggybacking on this- it's immediately apparent that Hubski's "follow the people rather than the topics" interface encourages the development of a strong online community, versus something like Reddit, which is really good at promoting the semblance of community. Reddit's basic interface allows us to congregate, as you already said, around an idea. Which is the basis of any community, online or off. The illusion breaks down, however, when you realize that the transactions on any given Reddit sub are incredibly fleeting- given that a) the size of any one sub all but guarantees that you'll never talk to the same person more than a handful of times, and b) there's little incentive to actively follow any given user, since unless they happen to post something that makes it to your timeline, you'll only ever follow them if you actively dig around for their profile. So ultimately, you get a bunch of discussions which may or may not remain civil and may or may not remain on the topic of your mutual interest, but which, more importantly, hardly ever build anything more than a fleeting relationship between the congregating users. And communities may begin around a shared passion, but they thrive through interpersonal connection.
I've only actively been on Hubski for, oh, about eighteen hours now. But once you get over the superficial similarities to something like Reddit, you very quickly realize that the interface encourages actual community-mindedness. By following people rather than topics, you're forced to a) choose carefully to relate to people whose conversational style and substance complements yours, and b) then constantly keep tabs with what all those people are talking about. It more effectively promotes deliberate personal interaction rather than incidental interaction around a given subject, and it seems to insure, at least at this early point in my experience, a level of civility that increasingly seems to be the exception, rather than the rule, around places like Reddit.
The conversations I've seen around here have been largely respectful and substantive. It's a really refreshing change.