Single Core - True, the iPhone 4s computationally flies, but I don't think this will hold the Nokia back. Gaming may be the exception here, but as long as the developers know the platform they're aiming for they're good at compromising (360 vs the more powerful PS3 for eg - there are differences in the games but you have to be eagle eyed to spot them) for day to day phone/email/music/internet etc, well, I've got a slower Win phone than that, with Mango, and I'm trying to think of a time where I wished it would hurry up, but can't. Need for Speed is probably the biggest CPU killer I've got on there and I've noticed very occasional slowdowns, but hey, it's not like it's a COD deathmatch or anything :-)
Pixel Density is not that great, but Super AMOLED whoops backlit LED out of the park - the colours saturation and contrast are simply amazing. Seeing the two side by side and the iPhone looks like one of those ancient LCD color efforts - despite the extra pixels. I think Android potentially has the edge here, with it's many platforms able to regularly push the envelope on what's possible, although I don't think there's been an AMOLED with the density of the iPhone - now *that* would be awesome.
No US launch before Christmas - yep, that's a massive air swing, but with Nokia circling the toilet, this launch is damage control, the next one will be the biggie.
Pro's
I don't know about the camera either - Nokia are usually pretty solid in that space though.
The N9-alike (what's it called again??) is a nice bit of kit, feels really solid and nice in your hand. It's a smidge smaller than my Omnia 7, which sharpens up the display a bit. The only thing that's weird - NO USER SERVICABLE BATTERY! How much flack do Apple get for that??
I'm not sure WP is actually lagging iOS - the core functions are there, it's solid. Massively in it's favor are things like the way it consolidates all your different data sources (LinkedIn, Facebook, Twitter, Outlook, Gmail, Hotmail etc etc) is unmatched anywhere. For me I like, for example, the way facebook events and My exchange calendar are now one - the number of times I've turned up bleary eyed for a meeting I've scheduled because I forgot it's so and so's birthday the night before... and they're right in your face on the lock screen. It's like MS have just gone, f*ck this, let's go over the top and be the number one aggregator. FB, twitter et al do all the underlying hard work and Microsft gives you this single window where everything comes together. It's fricken awesome! Also you don't have to plug in to all these services if you don't want to, but as far as I can see that's the biggest benefit of the platform. iOS is nice and all, but feels so last century compared to WP. Android usability is a bag of nails in comparison. (I know, I know, Android comes in to its own when you like to tinker, but on my phone, I don't, nor do lots of people, as evidenced by iPhone. YMMV)
The phone is comparable in price to a iPhone 4s, Build quality is similar, although the iPhone still has the edge on style I guess. Comparable featuresets which I think is better in some key areas.
The Windows Phone app store is lacking in absolute numbers right now but they've got one of every sort of app as far as I can tell. The problem is network effect, where all your mates are playing an iPhone version of scrabble or whatever, but you can't join in even though you've got a good scrabble game yourself. However, it's still nice when random people on the tube are interested in your phone because they've never seen one before (I've STILL not seen a single other Windows phone user in the wild!) still that's only a bonus if you've got no life I guess :)
You'll probably guess that I'm a bit of a fanboi, but I earn my living implementing MS tech, and wanted WP7 because Apple is the new Burberry, and Android is like making clothes yourself. It's fun putting together a Microsft platform at home that, like the fruit companies efforts, 'Just Works' and it can be done - I'm quite obstinate like that. :-)
Anyway, after I seem to have written a bloody novel... I'm hopeful for Nokia, I don't think this is the killer phone they are aiming for but it's been a really tight turnaround for them to get something out this quickly. They've got a big future, and a little bird tells me they're not quite completely MS's bitch like most here would seem to believe. They still have decent ambitions of their own in the smartphone market.