The viability list should be reflecting how the metagame is currently, not how it will be in the future. If Mega Salamence is impacting a certain Pokemon's viability, then said Pokemon should be moved to the appropriate rank to reflect its viability in the metagame. Once Mega Salamence is banned, then the Pokemon's rank can be changed again to reflect its viability in the new metagame.I hate to be the double posting dick here, but Stop talking about MMence checks cause MMence will be banned when ORAS comes out. He is AIDS to the meta and needs to die in a fucking hole in Ubers.
EDIT: Ninja'd