I think for the moment we need to start banning only the obvious ubers, such as Groudon and Kyogre (who would obviously centralize the metagame around their two abilities) and carefully explore the clauses that exist in singles. Sleep clause seems to be the most controversial, but Evasion, OHKO, and Item clauses are also major changes in the VGC rules from our own. Before deciding that we need a Sleep clause we have to realize that double battling is much faster than singles, and thus items such as Leftovers are replaced by Lum Berry, Chesto Berry, Sitrus Berry, etc. Because of this much larger focus on berries Sleep is not always game breaking and sometimes turns out to be a waste of a turn. Additionally I believe a rule-less and ban-less metagame should be used to start, this is an entirely new metagame from singles and it requires entirely new rules and ban lists, nothing should be transferred right away. Centralization should be easy to spot in a doubles metagame and the appropriate action can be taken during the course of testing.