I think it's awesome that other costumers are making Disney Princesses to wear at various events in 2012. (I'll be at Dress U (maybe the tea?) & Costume College (Ice Cream Social I think)). The more the merrier I say - I love it when costumers make the same thing because, in fact, it's never the same. Even with the same inspiration (an illustration, an extent gown, a fashion plate) we always end up putting our own personalities in our work (that combination of talent, taste, skill, fabric finding-fu and budget will always make your costume scream "you"). I think it's great fun to see the variation and different twists on the same theme.
Sadly there is already some walking on egg-shells going on with the various groups that are forming. Having to fear the potential of people being petty and proprietary (the "it was my idea to copy that first!" syndrome) is a such a shame. No drama has actually erupted, just the fear of it, and I hope it stays that way. Seriously people, the costuming/cosplay world is plenty big enough for all of us to be Disney Princesses in 2012 if we want to.
In that spirit