I'm a big fan of moving quickly. Moving now, instead of waiting can often give you a signifiant competitive advantage.
Being early to catch trends, shipping when your competition is still in the planning phase adds up over time.
But sometimes jumping the gun isn't always the most intelligent path forward.
For example, in my haste to try the new Mac OS, I updated my computer using my dev account, when in hindsight I probably should have waited for the public beta.
It's buggy, many of the apps are freezing, making it difficult to use. And for what? For a few extra weeks of playing with it at most?
Most people default to moving too slowly. But sometimes it's best to wait.