Since I didn't really see an official thread about hands on impressions from community members apart from Qole's hands on from Nokia World I thought I would start one so us regular community folks can talk about experiences.

Today I went to the NYC Nokia store and had about 30 - 40 minutes to 'play' with a proto N900 device without supervision of any kind really apart from a manager occasionally coming over to look and here are my impressions.

Hardware -

The device I held was a prototype according to the rep who was there. The build is solid, very solid, albeit a little chunky, think N95 8GB. For those of us used to pocketing N810's it is definitely much smaller and easier to slip into a pocket. The slide mechanism feels 'right', with the right amount of heft to its movement. The screen lock mechanism slider was appropriately placed for landscape use.
The keyboard has a very nice feel and is exponentially better than the N810, the only problem is the 3 rows, which aren't ideal but for me not a deal breaker.
The screen is gorgeous, the size difference from N810 to N900 is noticable but the resolution is so nice that its quickly forgivable.

Software and Experience

For a seasoned tablet user this is a very interesting change to maemo. It really feels like a hybrid between maemo and s60. Maybe its just the icon change to the Nokia standard icons but it is weird looking at the s60 icons to invoke messaging, contacts etc. I tried out pretty much everything I could but there was no sim in the device and I was on a pretty poor wifi connection.
I tried to tether to my 5800 on ATT 3G but the bluetooth on the 5800 kept on turning off so I just gave up.
The kinetic scrolling on every screen was great. Switching desktops was a breeze and I could see how great it will be to be able to run complete desktops with different purposes, work, play, media etc.

There is a nice polish and sheen to things such as application manager. Within the application manager (it was the Extra's enabled not extras' devel) there are some interesting widgets. An AP news streamer, an amazon widget, Dataviz documents to Go and some various plugins such as Picassa support, Qik etc. The wifi connection was so bad I couldn't download the 5.2 mb Dataviz suite after 10 minutes
If packages are appropriately labeled browsing the repository should be an enjoyable experience.
The media player seems to be proficient enough that most users probably won't need to use an alternative player. I plugged in a set of headphones some decent quality earbuds from Shure and listened to the music player with the stock mp3's. It sounded decent I couldn't tell a difference between the N900 or my iPod touch with probably a 160-192kb mp3. I played the N900 movie and it looked stunning. The speakers are not as loud as the N810 I think but still pretty damn loud with good separation.

I tried the bounce game and the graphics were amazing, very high quality and the accelerometer seemed very sensitive and well tuned.

Web browsing on the device was really, really good if not great. I have been spoiled with Bundyo's Tear and I can't wait to see what that browser can do on this device. I loaded up a few websites such as facebook regular and lite, CNN.com, espn.com and had them all running very well in different windows. I then loaded youtube and noticed my first slowdown from using the device. I had some very heavy pages loaded but I think saying that you can multitask EVERY window is a bit of a stretch. Once I closed espn.com the youtube site seemed to respond much better. I had no stuttering at all which was strange as the wifi connection was so bad. That video from jkk seems to be an anomaly or perhaps he had too many windows open already.

The camera took high quality pictures and processed them very quickly, definitely the same quality as an N96 or N97 though. No services were setup and I didn't feel like logging in with any of my personal accounts but all the menus popped up quickly and smoothly. I wanted to bluetooth a picture to my 5800 to share here but once again my 5800 failed

I added a contact and saw there are so many fields and contact services you can enter you can lose count quickly. It is very easy to add these. As I mentioned before there was no SIM in the device but I did test the portrait mode and held the device up to my face. A little big but definitely usable.

There are many more things I did but I will stop here. The biggest thing I can say is that Nokia have something special here. Even after using s60 mobile phones for years and maemo tablets for years, there is something great about having all this power in your hands/pocket with OR WITHOUT a cellular connection. The increase in processor power is exactly what maemo needed to truly realize its destiny. This does not feel like a phone yet though, it is still a mini - computer. The sheer amount of customization completely destroys the competition and will be a blessing for some users and a curse for others. You can do as much with the N900 as you can any netbook and then you also have a phone capabilities and multimedia capabilities. Once Easy Debian is up and running with a bluetooth keyboard and mouse you will have a great little palmtop.

I can see why Nokia is labeling this a multimedia computer and not a smartphone because comparing this experience to an iPhone or a Blackberry is actually unfair to all of the devices.

Needless to say I LOVE THIS DEVICE am going to buy one as soon as they are shipping and I am going to dump Symbian probably for ever.

Questions? ( I will try and answer any questions people may have over the weekend). If you go to Nokia flagship in NYC they have two protos I think behind the counter, just ask. I wasn't able to shoot anything I had my little HV20 to do some HD hands on but the manager refused to let me shoot.