let Keynote reevaluate all cells of the next slide

gistfile1.applescript

tell application "Keynote"
	repeat
		set allSlides to slides of front document
		set currentslide to current slide of front document
		set nextSlideNumber to (slide number of currentslide) + 1
		if nextSlideNumber < (count of allSlides) then
			set nextSlide to item nextSlideNumber of allSlides
			repeat with aCell in cells in every table of nextSlide
				set tmpFormula to formula of aCell
				if tmpFormula is not missing value then
					set value of aCell to tmpFormula
				end if
			end repeat
		end if
		do shell script "sleep 1"
	end repeat
end tell

It's just a really hacky proof of concept. I wouldn't recommend using this version for a presentation.