Scoble is right. All the research, value proposition positioning, and market playbooks can't save you from looking like a copycat. Waiting that extra year or even months to perfect something for the web certainly doesn't win you any customer mindshare.
The read write web means that people become more invested in a web site. If I'm just reading sports news it's easy for me to switch from Espn.com to foxsports. But If I'm posting pictures of my baseball games on flicker and I've built up a post history in a sites community I've just become invested in your site in a way that makes it harder for me to leave. So you're better off being the one with less features and more personal investments than the also-ran trying to win a feature race to make people switch.
Not shipping early also means you subject yourself to the classic "moving target" software problem whereby your clients needs are changing on a regular basis. Spending too much time on the "boil the ocean approach" means your exposing yourself to this risk of putting momentum behind ideas that are constantly shipping.
It's hard to make people realize that Apple's secrecy is NOT the key to their success. I'd wager that their leadership position in the digital audio market has a LOT more to do with shipping a limited, but cool, design... and constantly innovating on top of that design. Even though there are now going to be iPhone competitors it will be Apple's execution that determines if they are the winner. So success is more a factor of timing and consistent execution than world changing platforms in today's web world.