I want to move all BL Pokemon into UU. From there, Pokemon that prove to be worthy of banning would be banned to BL. It's entirely possible that we end up with the same tiers we have now, just highly unlikely, because I suspect there is a decent balance point in there somewhere. I am not for removing BL as a tier, and in fact, it is necessary. Under my plan, BL would just likely be a lot smaller. The quality of Pokemon in UU would shift up, thus allowing more Pokemon at the bottom of UU to drop off into NU (and its BL / uber tier, which is as yet unnamed). This raises the quality of the NU tier as well (which is one of my main problems with ADV UU, it's horrible for competitive play if strategy in team building is a desirable trait).
In other words, I'd empty out BL, but then slowly add Pokemon back to it, but this would be based primarily on actual playtesting, not "I think Pokemon X is too strong!".