I'm curious about fondant. What is it like once it covers a cake? Does it get dry, or stay soft?
In my experience, it dries out some. I don't think there is any way to avoid that. It's just the nature of fondant. It still tastes good once the cake is cut, though! 
Do you have to seal the cake in plastic wrap or something after it's done? Say if you cover a cake in fondant...or MMF the day before it's needed?
No you'd just store it the same way you'd store a buttercream cake. If you would put it in the fridge, then do the same, it depends on what fillings the cake has if it will require refrigeration.
Nati
i read that fondant shouldn't be refrigerated because it sweats. Was i misinformed?
Have a look at this post, it's all about refrigerating fondant cakes.
cheers
Nati
http://www.cakecentral.com/modules.php?name=Forums&file=viewtopic&t=41008&postdays=0&postorder=asc&&start=0
It does sweat in the fridge. But I have left my cake out on the counter during the decorating the day before I deliever or they pick up with no problems. It drys on the out side but not to much inside. Unless you do it days in advance.
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