@ 50% that isnt too bad....I would hold off, chances of getting one worse @ 50% seem pretty high to me. However I would definitely watch your 14 day or return window period. If you are not 100% happy return it. Im past my 14 days and keeping my fingers crossed they allow me to warranty at a later date.
PS - I logged a complaint with Apple and call every other week to confirm my case is still open in their system.
See the thing is I waited for the iPad 2 so I had been waiting for over a year. I defiantly will not return this one for a refund but I will be picking one up for someone I know in canada before I go there this summer. If the iPad I pick up in June does not have the light bleed issue I know that it is safe to switch mine out (or I will just give them mine)
I will be opening a case with apple about the issue soon to make sure that I will be able to get a replacement down the road if they fix the issue.
For now I am going to have to live with it but at least my iPad screen is one of the better ones!