I haven't yet gotten my N800 (will be here monday), so I can't comment from any experience on that yet, but I can comment on some of the things I like/dislike about WM. I have a TDS Recon running WM 2003 I believe.

Software support seems to be great. There's a ton of highly-polished third party apps. My favorite has been Calligrapher. Have any of you guys tried that out? It's amazingly useful. You can set it up so you can write anywhere on the screen, the handwriting recognition capabilities are above and beyond anything I've played with before, and you can set up certain written symbols to launch apps, etc. Is there any way to do this on the N800 currently?

One thing I don't understand though, is the difficulty in getting videos to play well on the N800. Are you using OS 2008? With that CPU boost, I don't see why it wouldn't be able to handle vids well. My Recon has a comparably slow CPU (166Mhz, I believe), and once I figured out a good size/format/fps, I could watch TV shows on it just fine. Last time my wife took a trip, I filled up some CF cards with episodes of Family Guy and You Can't Do That on Television for the plane ride. Regardless, we've now gone off topic as we're talking about hardware instead of Maemo v. WM.

WM may have slicker apps due to more commercial development, but the attitude of the communities surrounding such devices is drastically different from the Maemo/Linux community. While there are a ton of homebrew apps for WM, the majority of motivation for development is "can I make money off of this?". For Maemo devs the question is more along the lines of "what can we make this thing do?" or "what can improve this device?" (notice the use of "we" instead of "I"). And with Maemo and OSS, we have nearly unlimited access to the functions of the hardware.

The Linux model is interesting in that it actually brings people together instead of isolating them. This is very reassuring, especially in the realm of technology and its largely ego-centric uses (mindless entertainment, facebook/myspace/twitter). While there is more work involved in improving things/getting them working right, the experience is more rewarding as it forces us to unite and have a meaningful dialogue.

Just my 2 cents.