Event Simulation. I suggest that this weekend you get together with your team for a two hour event simulation. Aim to complete 30-60min of each of the three disciplines, ideally with a navigational component. This is a great opportunity to check that you have all of the gear you need individually and as a team.
Rest. Including, but not limited to sleep, rest is your best tool when it comes to recovering from the rigours of work, family, life and training. How much? As much as possible. How rested you are will have a significant effect on the bodies ability to control key stress hormones during the event.
Due Diligence. Spend some time this weekend (re)reading through all of the pre-event communication that you have received. This is a great way of making sure that you don't have any surprises next Friday when you get to Taupo. I suggest you pay particular attention to the FAQ's.
Mountain Bike. If you haven't already done so, it might be worth getting your Mountain Bike serviced before the event. Do this sooner rather than later. It is devastating when teams are not able to finish events due to preventable mechanical issues.
Warn Your Family. You will more than likely be nervous in the lead up to the event. As a result of this, it is probable that you will not be your normal self. I suggest that you warn your friends, family, and colleagues in advance. Hopefully they will be able to cut you a bit of slack.
When all else fails, keep smiling, it is meant to be fun.