I was also surprised that the basic model was not upgraded to the new screen. I think the cheapest kindle is actually the best one to get, because of hardware buttons. I won't be upgrading it anytime soon, it seems.
Well, no. From what I can see, all the "PaperWhite" models have a touch screen (which I really do not want) and no hardware buttons (which I really do).
So, no upgrade path for me. I'm sticking to my current Kindle.