No leak on my 32gb...ordered it from amazon on monday night and got it yesterday (thursday) ... maybe i got lucky 
My last one was just two small dots that's like a millimetre, but this one's big. Is the white box refurbs?
Which is why light leaks aren't "officially" supported because mostly all iPod touches have it.
And no, white box with no labels mean that its a replacement iPod. Apple can't give retail boxes.
Refurbished means returned, fixed by Apple and can't be sold as "new". They sell refurbished iPods at reduced prices and use it for replacement iPods if applicable.
So I guess the replacement iPod I'll be getting might be that... I really hope the condition is going to be close to like new or very good since I've taken great care of the iPod I'm about to exchange it for.
I noticed that my iPod Touch 4G 8GB has tiny light leak of about 1-2cm on the right side.