I had a rev A. If I remember right, it feels just like my rev B.
I also have a unibody MB and older generation MBP. The unibody MB has a more stable (I guess that is how I describe it) keyboard. Each key on the unibody MB feels like it is on its own suspension, I guess that is how I describe it. The older MBP has keys that feel very plastic and cheap.
Sorry, I don't have a rev A right now to compare.
Of the three I have available, the unibody MB has the best keyboard, the rev B MBA feels ok, but a little more "flexible" than the unibody MB keyboard. The whole MBA keyboard feels like it flexes together... While the older MBP has the worst feeling keyboard, although I like the color the best