Was at Nokia Flagship Store and had a 15-20 minute test run on the N8. Here's few first impressions.

The good
It's kinda hard to express just how much Symbian has improved. My last Symbian experience was with the POS known as N97, and N8 is such a huge improvement.

First of all, there's no more excessive clicking and confirming connections and so forth. The UI really feels like it's optimized for touchscreen, unlike the S60 5th Edition which was just a T9 UI with basic touch controls tacked on top. It's also very responsive and snappy. Multitouch works well on everything except Ovi Maps (more about that later). Also the few apps that I tried and one game (Angry Birds) were all working well and loaded up nicely.

The store was packed with people and it seemed like everyone was pleasantly suprised. Actually it's been like a year, since N900, that I've seen people enjoying testing a Nokia device.

The Bad
Lack of multitouch on Ovi Maps was a pain, especially cause multitouch was implemented on everything else and it was really akward to 'dowgrade' back to single-touch.

I'm also bit sceptical about browser rendering speed. The new Qt based Symbian browser won't be out until November/December and the old browser currently in N8 is propably as slow as in S60, but I can't really say that for sure, because there were so many people playing with N8s that the network could'nt cope and everything requiring net-connection crawled at snail pace. On the positive side, scrolling and pinch-zooming was really smooth and fast on the couple of pages I had the patience to load.

Overall
Not really a phone for me, but very good phone for the market segment it's intended for. And all Symbian haters should definately judge S^3 on it's own merits rather than those of S60 5th Edition. Oh and please stop linking to that one and only Youtube video which shows S^3 as unresponsive. The net is full of much better videos, and the real world performance is nothing like that.

Galaxy, Iphone 4 and their ilk don't have to lose any sleep, but N8 is gonna offer some good competion to iPhone 3GS and similarily priced Android handsets. The cheaper S^3 models (C6 & C7) will make it really hard for Android to eat that Nokia dominance in mid-range.