I already sed i think users will play both.
But about that stuff AK not being different. I mean no it wont be the same. But actually AK has not just one person working on it, like FH have.
I am pretty sure AK will come along with much more features than FH. And it will have Items. Items are the most addictive things to many users.
On AK, theres the actual gamemaker, some other coders, designer artists, animators. They have probably done already very much, but unlike FH they arent sharing the info, which is the best they can do.
I can just guess it, but since i know who works on AK and what they actually work, and i know they are darn goof in what they do, i am very positive that AK will have much more stuff than FH. Not saying they will have better stuff, but more.