I also really really want to see a laptop with IPS 1920x1200 panel as 1080 is not enough for me.
From the perspective of such keyboard, I was holding on to E6410/E6510's for a while, but then made an upgrade to E6530 which allows 16Gb RAM easily. What I also did was replaced LCD with a Full HD IPS panel. There's no direct match that would fit right in, however, E6530 lid has enough space to put newer IPS panels like LP156WF4(SL)(B2) after removing a few things like indicator lights and some plastic pieces. Overall, besides the sucky keyboard that E6530 has, that IPS replacement was really worth it.
I also tried E7440 which comes with a Full HD IPS screen already, but it seemed at 14", letters were a bit too small for me. Another problem is that the IPS version is touch-screen and is glossy, while I really need Matte panel.