I've seen some youtube video's of the 700, but it basically uses the same screen and amount of greytints.
I'm really not convinced the 700 is much of a step forward. The side leds make it look like a primitive PDA, and you're forced flipping pages with the touchscreen.
However I'm not fond of the buttons on a 505 neither. Clicking buttons need to be of high quality will it still function 2 years and maybe 200.000 pages down the road...
I'm only basing my presumptions on the pre-order page of Sony:
http://www.sonystyle.com/webapp/wcs/...52921665562069