Have em on my new T430. I have to say, as far as chicklet keys go, they're probably the best I've used. I have compared them firsthand to the keys on the Macbook Air, and they have much more travel and tactility. They give you a nice little "thock" with every key press, though not in the ballpark of Cherry Blues or the Model Ms of old.
Compared to the traditional Thinkpad keyboards, the feel is almost the same. A little slipperier, because of the method used to create backlit keys. I hear that the non-backlit version has a more textured feel. Backlit keys also look nice and work well, while still retaining the thinklight for reading documents along the side of the computer. The redundancy could potentially mean that they'll do away with thinklight within a few models, unfortunately. Trackpoint is the same as ever. You either love it or hate it.
As for the layout change, it's a mixed bag for me. I'm particularly unhappy with the ctrl key being swapped with the fn key (you can change functionality in BIOS, but not the legends,) and no more fn key combo to disable the trackpad. The delete key is a little too alienated, meaning that you may have to pick up your hands to get at it. The placement of the printscreen key, between right ctrl and right alt has been useful, as I never used the menu key it replaced anyhow. The forward and back browser buttons above the arrow keys were changed to page up / down, but I prefer this, as it lessens the irritation of accidentally pressing the wrong button. You've always got the trusty backspace and shift+backspace duo. I also applaud them for finally getting the cohones to remove sysrq. Was that key ever used for anything??
All in all, I don't think the new board is a deal breaker. What was lost in layout was made up for in key feel and the option for backlit keys. The new layout isn't particularly terrible either. Any opinions from other owners?