Mr. Stoup did the math that was a long time coming and surveyed Think Secret's reports on Apple products between January 05 - September 06. You should really check out the results, as he did a bang-up job detailing everything he found, but to summarize: James found that Think Secret's accuracy can get pretty black and white; either they nail it or they couldn't hit the broad side of a barn with a wrecking ball. He also discovered some patterns in terms of which kinds of products Think Secret typically nabs correctly, concluding that they have a fairly good batting average with Mac hardware and iPods, but their 'inside scoops' on software tend to represent that aforementioned wayward wrecking ball.
Take a look at James' post for the real (and thorough) details of his findings, but don't think he's trying to bash the rumor gurus, Think Secret or otherwise. After all, what Apple fan doesn't hold at least some place in their heart for rumors of what shiny new thing Apple might have coming up? I think James' investigation should serve at least as a reminder that rumors are exactly that: rumors, and not much more. One is merely rolling the dice when reading these sites and building up hopes of a fancy new [insert name here] or a product revision.
With that said, we'll be sure to stay on top of the latest gossip to make sure y'all can decide whether the latest iPhone or media center rumors could be worth that extra wait.