Technology provides value to business by simulating and automating business processes. The measure of business software, whether client or web-based, is its ability to transform Business State A into Goal State B with the least amount of human intervention. Done right, it's about process engineering, not decoration. Business fundamentals haven't changed in ten thousand years, but they're accelerating as we automate. This rule never breaks.
Maybe it's just me, but I can't remember an instance where sticking plastic hearts or stars on file folders helped me find "good content" faster. To each his own criteria, yours probably isn't mine (also a rule by the way). The little green "this answer solved the problem" on Microsoft newsgroups gets it right for me maybe 25% of the time, it's not bad. I don't doubt it solved the thread for whomever put it there, but three out of four times the answer I need is either on some other page or isn't yet documented.
Now if social computing finds me an expert two floors up and down the hall who can solve Business State Q faster than I could with a coffee room bulletin board or a week of "asking around," fantastic. Type-written index cards with subjects (keywords) to cross-reference libraries, that was useful metadata. Top ten lists a la "here are the ten best books on subject x," those are great.
Which brings me to Twitter, which is where this train of thought began. I'm thinking "Links to links? Now that's just silly." I'll click three levels deep if there are actual choices along the way. Start me down a click tunnel and I'll avoid your links even if you one day find beer on Mars.
Is Twitter the Blackberry of blogs? The Blackberry turned e-mail into instant e-mail. Twitter instantly broadcasts the state of your ego (or web browser) to the masses in <141 byte-sized pieces. Like any good tool, it's exactly as useful as the person wielding it. When it simulates what goes on in the real world and makes it better by reaching the goal faster, it's good technology. When it's used to say "here's where I was today, maybe you want to go there too" it's about as entertaining and as productive as TV.
Eleven years ago on my first web page I joked that the Web was the bastard child of television and CB radio. Funny how we keep coming back to that. All I can add is that: if now you can use the rule of good technology to slice through junk and figure out which tools will help reach goals faster, then maybe you can figure out how to automate it.