I don't think it would be fair to change the rules for this upcoming season. Players may have made trades or roster adjustments counting on only having to name 1 keeper.
You should vote on whether or not to change the rule and, if it passes, have it go into effect next season (2005). That way owners can prepare for the extra keeper with the draft and as the season progresses. That's assuming that you don't get 100% that want it changed. If that's the case then change the rule right away (obviously).