The "walled garden", through it's closedness perhaps inadvertently, provides direction, cohesion, and leadership. There's a path to follow. It makes it simpler for the vendor to provide things, like a commercial app store, because it knows the type of apps that will be supplied through it. Documentation and apis can be developed knowing there are only a subset of languages that will be used, books start appearing on Amazon as the target audience is much more defined. End users aren't bothered how the app was written or if it was deved on locked down iphone sdk on a required Mac or open source Eclipse, only what that app does for them. This open sourced experiment of the n900 seems to offer plenty of potential but along with that are more complexities, fragmentation, and very little leadership from Nokia. And that's reflected in application development and customer base.