I'm a lover of negative space, this has plenty :) for me, the 'poofy' scarf could be sharper and it looks like you over corrected the exposure in the RAW converter to get the bg pure white?
I do like the idea and look forward to seeing version 2 ;)
colorful and good use of negitave space. Only thing I might change is to back up the background a bit and off set the flash a bit to keep the shadows from perfectly mimicing your subject. Hope that isn't someones hair.