Marginally better than expected.
But certainly worse than what I hoped for. The iPhone 3G is a marginally improved device that builds upon the very solid foundations of the first iPhone by adding 3G connectivity (though without the video conferencing part) and version 2.0 of the software and does this at a significantly reduced price --- which is probably the highlight of the keynote. It's also available in many more countries, including Hellas.
While I may get my hands on one pretty soon, I still think that the Nokia N95 is a superior device in many ways, and one that's mostly hurt by the vastly inferior (from a usability point of view) application software stack. The new iPhone seems like a buffer solution to the consumerism that brands the original as 'old' and whose price and attractive featureset, augmented by a software ecosystem, wider availability and faster network performance are certainly going to serve as catalysts while it becomes a(n even more) mainstream product and expand Apple's market share in this difficult market. That is, until a much evolved model appears in 12-18 months from today.
Update: I've already read several comments about the contract prices in various countries; it'll be interesting to see how this plays out in Europe and especially in Hellas, a country where mobile internet access costs about 70% more than the US. If 3G access is forced onto consumers buying the iPhone (which it will), the adjusted $199-$299 price points won't make a difference to people --- especially if the contract means a monthly cost higher than €30.
Update 2: It is now blatantly clear that the price reduction, even in the US, is marginal at best; the new contract coupled with higher prices for data connectivity make the new iPhone cheap to buy, but expensive to maintain.