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.
Matt MullenwegHistorically, WordPress has been purely focused on the writing side. However, were thinking about mobile completely differently, and I think theres a big opportunity to take the community of creators that loves WordPress and deliver an audience to the amazing things theyre making.
Matt MullenwegPeople might start with LiveJournal or Blogger, but if they get serious, they'll graduate to WordPress. We try to cater to the more powerful users.
Matt MullenwegYou can't build everything and there is no more a killer feature. Everyone has a different killer feature.
Matt Mullenweg