If most users are to use desktop-grade applications on the N900, there needs to be a simple way to install them. Easy Debian will provide just that, but it’s not quite up to the task yet. Advanced users willing to do some beta testing will find it exhilarating even now. More here
Current generation phones still have some of the technological limitations of embedded devices. The fastest flash device on the N900 comes with only 256MB of storage for the root partition. Even though Nokia adds a 2GB partition for /opt on slower storage, the size limitations preclude offering desktop apps directly in Maemo.