Mashable has quick interview with WordPress founder Matt Mullenweg focused mainly on creating a business based on open source software.
The biggest challenge for Open Source is that as it enters the consumer market, as projects like WordPress and Firefox have done, you have to create a user experience that is on par or better than the proprietary alternatives. Traditional Open Source development models, like the Apache one, are not set up to do that. In server software options are good — in consumer web interfaces they’re a cognitive burden.
While I personally believe strongly in the philosophy and ideology of the Free Software movement, you can’t win people over just on philosophy; you have to have a better product too.