The Standard has an interesting analysis of what a National win in 2011 might look like. I think the most likely outcome is a National minority government dependent on the Maori Party for support. Act will most certainly be humbled.
But the real problem for the country in 2011, in my mind, is the potential return greatest raconteur of recent New Zealand political history: Winston Raymond Peters. If there's anyone in politics who stands for personal advantage over national interest, it's Peters. I hope the Prime Minister once more rules out doing a deal with him, as was the case in 2008.