Well, it's different information. It is nice to know what it's about, but I'd rather read a random news.ycombinator link than a random article titled "Do Tiny URLs Suck".
I wrote shorty (http://github.com/bradgessler/shorty/tree/master), installed it on heroku.com, and hooked my own URL up to it so I could enter concise, descriptive shortened URLs. Its not for Joe Shmoe but if you're a geek, check it out.
Really, it makes that problem worse. I've had it burned into my brain what a shortened URL looks like - short domain, short hash - so I can immediately recognize one and be suspicious of it. But looking at http://tinyurl.com/Do-Tiny-URLs-Suck, I may just click without realizing what it actually is.