Here's my thoughts, probably should just start a new thread for a sticky. I've seen some guesswork on people's blogs and post and I've tried to get detailed answers from some food scientists.
here's what they're telling me (based on their knowledge, but I did ask if they tested it and they said they hadn't)
You CAN brine an enhanced bird. Why? And no, you don't need to reduce the salt.
Brining works by Osmosis. The idea is that you have a higher concentration (brine) and a lower concentration (bird) and through brining, they achieve equilibrium.
So, that last word is important.
Brining an enhance bird doesn't ADD salt to an already salty bird because the equilbrium will try to be achieved between the % of salt and the two objects.
It's just not an additive effect.
Thus, when you brine, if for example the bird is technically saltier than the brine, it won't take on more salt.
Instead, just the opposite. The brine will draw out salt from the bird.
So, technically, you could soak an enhanced bird in water and it would reduce the % of salt. The problem is it's not just enhanced with salt, but more stuff.
So, I have tested this with the family an friends. I've brined in my Turkey 101/Brining 101 brines my normal 48 hours and no one indicated it was salty.
I've done the test with enhanced birds up to 15%. I haven't test over that percentage (because I didn't want to buy them).
Your individual mileage may vary.
Oh and FYI, the brining 101 link was broken this weekend and should be fixed today or tomorrow. If you want it, just PM me direct.