If you're buying now, there's no doubt which one to go for ... D70. It's much more capable, and cheaper, than the S2Pro.
And this is coming from someone who's shooting with an S2Pro ! :bsmilie:
But the S2Pro has some good points as well, eg. can do proper 3D TTL flash with all Nikon Speedlights, while the D70 can only do i-TTL with SB600/800, I think. But I could be wrong ... read up on it over the internet, lots written about both cameras.
I chose 2nd hand S2pro over new D70 just about 2 months ago. No doubts in me, Fuji colours is my choice (I was on the S602 for about 1.5 years).
Technically, the D70 is MUCH more advanced and more robust. Straight out of camera, I prefer the S2pro. And not to forget the instant "12 megapixels" with a quick button press, low noise and high colours.
S3pro? Announced officially $4k, I estimate street price of $3.6k. S2pro new is about $2.6k, 2nd hand $1.8k to $2.2k. Go figure!
I'm a S2 user for a year already. The colours and the extra pixel info can't be beat for my needs (though some pple will debate on F80 bodies and on interpolate pixel). Be warned, though - if you are a casual user and the fire-more-shots-than-needed type, go D70. S2 Pros are dust magnets, requiring good users to draw the best out of the cam. My personal opinion.
i personnally will take on S2 , reason being colours reproduction is better than D70 nad also looking at it interpolation . no doubt about the pixel size.. very refined .. it feel more solid being held in hand than D70. will i find too small for my liking. No doubt other have swore to D70 being light and fast on storage in shooting jpeg.. but looking at all this.. many people are sellign away the 70s faster than i have seen during the D100 era.. Why.. some of them are less than 6 mth after they have bought it. ... maybe they can explain why ....i dun know... my friend even wanted to sell his D100 away after some time he gotten his 70-200 AFS..and get a d70.. BUT even before the D70 is out .. He said he wouldnt even think of it...