the last three houses we had, we left the paper and wallpapered right over it. if you have trouble getting it off, believe me, it isn't going anywhere really soon. use a little filler, like spackle, to smooth it out where the old paper meets itself, let it really dry, and just ignore that it's there at all. after all the work you did on the cabinets, the last thing you want to do is use a steamer in there. it can warp the unfinished cabinet bottoms.
the kitchen looks like a brand-new room. now keep everyone out so it stays that way. :wink: