I like the idea of a Nike logo parody with a banana peel... but it is too subtle... all I see is a guy slipping... that is where my attention is drawn. What if you just had a shoe with that logo on it?
two issues with it:
1. like Resistance said, it's almost unnoticable (didn't see it till i read the comment), but that can bi fixed with color combinations, placing and size;
2. will it infringe Nike's copyrights? if you make it similar enough to be obvious, and have it on a T-shirt, it's slippery territory (no pun intended with the "slippery" remark ;-))