I see no need for an entirely new government at this time. Perhaps a few tweaks to guard against a repeat of 07/21/07 and to get the community more involved.
Personally, if I were to rethink a government from scratch I'd say monkey with the NS system a bit. I would suggest dramatically decreasing the time requirement for become a voter so that citizens may become more active more quickly. Additionally, have a branch of government devoted to maintaining the founder nation (perhaps a charge for the Judiciary). The Senate would be defacto elected by consisting of the top 20% most endorsed nations in Taijitu that hold citizenship and voting rights but do not hold a post as the Executive or in the Judiciary. From there things could progress much as they do in RL US government with a few game related changes. The Judiciary would be required to use the founder nation as per any instruction given by 2/3 majority of the Senate, typically for the purpose of restraining a rogue Executive. The Minister of Defense would also be barred from a senate seat as their nation would also hold a large number of endorsements for the purpose of maintaining a significant military force at the ready.