Hi Cem,
I've been playing around with it for a few days now. Haven't looked much at the new 'Book' module yet, and have instead spent time in the Develop module and the Map Module. Sorry Asher, haven't tried tethered yet either.
Most of my photos are landscapes, so the Map module is nice addition for me. I'm normally quite good at putting the metadata into my images, but being able to browse geographically using Google Maps data is nice. Of course my images don't have GPS embedded by default, so it's been a case of dragging images onto the correct location first, but to be truthful this hasn't been too much of a hardship.
At first I didn't like the re-worked sliders in the develop module, especially the new style clarity, but now that I've spent more time with them I think I'm actually getting better results quicker. To me, the ability to pull up detail from the shadows without artifacts/halos is now much improved, and in general there seems to be better highlight protection as you move the sliders. Individual point curves for RGB channels are a nice addition for those occasions where they're useful.
Agree that soft-proofing looks well though out and well implemented - a nice addition.
No crashes for me yet! Vista 64-bit on a Core2Duo. Just ordered a new WIndows 7 PC though (i7 2600), so we'll see what happens with that!
Would be interested to hear thoughts from others who tried it,
Andrew.