Don't take this to the bank since I haven't been following this that closely:
A) is it a compatibility issue wherein the iPad will not play a Mac created version of keynote file perfectly?
or is it
B) The iPad does not have all the bells and whistles to add or create a file as deep and cute as a mac derived keynote file?
I would be worried about A and not be concerned at all about B. Who wants to create a Keynote file on an iPad? MAybe resort or delete a slide but that's about it. I just want it to play it when I walk to the podium. I am aiming to do that a few times in September/October with an iPad. I'll certainly have the MBA close by as fallback.