Impressions of a Windows user:
Just for reference the last Apple product I bought came with OS 7.5.3 on it so go easy on me

I bought the 15GB version. This thing is small, like deck of cards small, maybe even a bit thinner than that.
The backlighting is really nice and bright but the timer has some issues. It seems to count from the time you first hit a button and stays on for a certain period of time, this means even when i'm still hitting buttons it will go out and i'll have to stop whatever i'm doing so it can register that I'm going to hit a button before. Always on is an option but then my pocket sort of glows .
The touch buttons can be sort of annoying since they are pretty sensitive, when i have the ipod in my shirt pocket just leaning forward or back can set off the buttons. Placement of the wheel at the very bottom of the ipod makes it a bit awkward feeling to operate with one hand. I guess i like the feeling of my thumb on the bottom of the scroll wheel rather than the top, and to do that i have to basically grip at nothing on the bottom.
The dock is much smaller than I imagined it would be. I was thoroughly impressed by the level of detail apple takes in packaging their products, everything was wrapped up in a tidy little package. When i'm docked I can't play music out of the ipods earphone jack. There is a line out on the dock but I haven't figure out how i'm going to hook that up to anything to effectively play. I guess the reasoning is if I'm at my computer docked I can play my mp3s through winamp (itunes for you people).
The earbuds are nice enough, but i'm not a huge fan of earbuds. I tried my Sennheiser 495s and the ipod seems to struggle to drive them. I haven't figured out how i'm supposed to use this remote. For one thing the wire is like super long and the long headphone wire clips into it, so I've got like a ton of slack to put someplace. Also the remote has like a lapel clip on it but it's one sided. The one side it can clip to is like the complete opposite of how all men's shirts button up. Meaning if you are looking down at your chest it wants to attch to the right, but the shirts have the loose material to the left.
The metal shows a lot of fingerprints, might've been a better idea to do the brushed aluminum thing since unless i have a buffing cloth handy it looks a little ugly with the prints.
Musicmatch is teh suck. Took me 10 minutes to figure out how to transfer songs, I still don't have all this playlist thing down. Trying to figure out how to import my Winamp playlists, it says it can but I can't figure it out. Ephpod and Xplay look like good alternatives but neither really supports these new ipods with their v.2.0 software. When I have it docked the ipod always flashes "do not disconnect" with a big crossed circle sign. Sort of annoying. If I just have it plugged straight into power adaptor it shows the more pleasant charging symbol. Windows automagically recognized the ipod as a HD so i can see it and all it's folders in windows explorer. It uses a wierd catalouging style though so I can't just really drag and drop songs onto it for playing, only if i want to transfer them to another computer. It basically forces you to use music match/itunes for the transfer i guess.
Played a quick game of solitaire today, takes a little getting used to using the scroll wheel for that. Haven't tried any of the contacts, calendar, or notes features yet as I don't really have a need for them.
All that said I think I will really enjoy it and get a lot of use out of it, especially in the car since radio stations are crap anymore and I don't have a CD player.