I have had 2 N800s and got aniPod Touch 16GB this morning. It already pissed me off.

Good things first:
-Package management. I have been linux user for years and have always taken the ability to navigate categorized lists of software for granted. The ability to do it with the iPod is really good benefit.
-Unix under the hood. Terminal, essential GNU utilities. What more could I want (:
- Massive Sound. The volume is uncomparable to a N800. Right now I have only basic headphones, but it doesn't seem to me to be extraordinary better.
- Formfactor. The thing is damned small!

The bad:
-ITUNES. MAY ALL APPLE SUFFER FROM SLOW AND PAINFUL DEATH!
Why should I use this crap for all thing iPod/iPhone? I am a linux only user. Yes, amarok, yes, but my wifi router died and the only way now is with USB. I can't restore/update the device. Under VirtualBox/VMWare it's broken. I digged out from the basement an old Celeron@500Mhz machine with Win 2003, but as it turns out iTunes doesn't work with older CPUs (QuickTime error 2096).
-Single tasking. What more can I say. I almost feel nostalgic about the DOS days.
-No BT AD2P. It's 2008. There are plenty of stereo BT headsets. No need to get entangled in wires, full control of the player without even looking at it. After all this is a multimedia device...
-Relativly simple applications. Not that I need Photoshop up and running, but I haven't found anything really spectacular aside all that jailbreaking stuff, a few addictive games and one great last.fm client. The community around this platform is relatively new to the Free/Open Source idea, the Official API is a little bit restrictive and came relatively late for the big software vendors to start releasing stuff and existing FOSS needs to be extensively ported to the open API, which is far more complicated than just recompling stuff for the ITT or even hildonizing it.

Just my 2 cents.