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.
Click on the screenshots for full resolution.
Why a Separate System?
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.
Even with more space, it makes a certain amount of sense to keep mobile and desktop apps separate. If a chroot environment gets damaged due to badly behaved programs, the phone and all other mobile apps in the Maemo repositories will still work.
Easy Debian solves both issues by running Debian programs from an image file users can place on the 27GB FAT32-partition. Once it qualifies for the Extras-repository, the average user will be able to install it from the Maemo package manager, and then new programs using Synaptic.
The largest problem I ran into was that no KDE apps I tried are accepting input from the keyboard. It appears to be caused by a bit too much mobile optimization in the window manager. I wouldn't be surprised if someone is already working on a patch, but in the meantime Easy Debian must find a workaround before it can be considered ready.
Even now, though, Konqueror was already useful to me. Controlling it with a stylus works surprisingly well, and by specifying the address on the command line, I was able to quickly get some music off my smb share.
Another strange issue is that the default image file is so small there's virtually no room to install anything on it. This may have made sense with previous products, but the N900 has so much space that the only reasonable size is the full 4GB that FAT32 allows for one file (groan).
Advanced users can obviously create their own image, but why use Easy Debian in the first place if that's the case? (Although, to be fair, it does do more automation than just mounting the image, such as making the Maemo home directory available inside the chroot.)
Sound doesn't work, but we should remain hopeful that the Easy Debian developers somehow manage to configure PulseAudio right. I wouldn't hold my breath, but a fully functional PA would be wonderful. The N900 should be an excellent platform for testing network transparency features.
If the mouse pointer in desktop apps is off from where you're pressing, go to the phone settings and play with the recalibration tool.
My Advice: Ditch the Theming
The first thing I noticed was the horrible effects a mobile theme has on desktop applications. It's obvious that the intent is to increase finger-friendliness, but I am convinced that the developers will never get the themes to show enough content on screen. There's a reason the N900 ships with a built in stylus - so let's use it for what it was intended.
For comparison, here are some screenshots of atrocious "Maemo"-themed applications next to beautiful and usable KDE-themed ones, which really showcase the usefulness of Easy Debian:
Another application many users should find helpful on the go is Wireshark, which performed well, and would be totally unusable with a finger-friendly theme:
Games Need Keyboard Remapping
I installed Abuse, and while aiming with the stylus was a breeze, the game is unplayable unless you're left-handed. Several other games that didn't natively support keyboard remapping refused to work entirely, as I just couldn't press the right buttons at all. This is exacerbated by non-English keyboards that sacrifice up/down for extra letters.
The only solution to this problem is someone writing an easy remapping tool that lets players quickly substitute wasd for the arrow keys etc. (Actually, the only 100% playable option would be qw for up, a left, s right, zx down, because pressing a vertical and horizontal key simultaneously is too hard with wasd.)
But here's a screenshot anyway: