Well the RAM and SSD's will meet user expectations. The prices are going to push some MBP guys into iMacs I suspect though. Maybe not in the US, but in the UK and parts of Europe.. going to be hard to afford these.
Lets see though. Can't wait for the official release
I would take a thicker, heavier 17 inch version with longer battery life any day. Reducing the size of the screen so you can have a higher DPI is not a good trade.
That, I would buy. Glad they got 16GB RAM in there. I really need it. But @ $4k? Then there won't be a 27" monitor to go along with it. Maybe there's a non-SSD option for much cheaper?