UPDATE: Got the chance to fondle one over the weekend.
I saw a .40 caliber one in Charleston SC at ATP Gun shop for $609 -- its important to note that they are a pricey store, and all their other Glocks sell for $550-$600
*The new grip texture is great. Its not too much like the RTF was, but it really adds a great deal of "grippyness" to it.
*The backstraps are pretty slick. Not sure which one they had installed, but it had a much more user friendly grip angle. It is also very well done. If you did not know it was interchangable, then you would not be able to tell. It looks like the frame and backstrap are all one piece.
*The new frame also feels thinner. Not single stack thin, but it is a lot less "Blocky"
*I did not care for the new mag release. It is larger, but it is also flatter and would take some getting used to. Its like you really have to search for it and find it. I could see how it would be a problem if going back and forth between it and other guns.... or earlier model glocks.
I think there is some real value added for consumers with these new models. As long as they sell at a reasonable price point, and there are no issues with the internal changes I think these will do very well.