Save battleplan draft
This would allow you to deploy armies, make movements, play cards, then save those plans instead of committing them. This is important because it allows me to create and review my plans over a long period of time without keeping my browser open the whole time.
It’s now possible to save orders and come back to them later! Check the announcement here: http://blog.warlight.net/index.php/2013/09/experimental-feature-orders-are-now-saved/
The Impaller commented
I've wanted something like this for a long time as well. In some games on huge maps (like Big USA) it can take 20 minutes to enter in your orders. It would be nice to save your progress, especially if you are in a team game and don't want to submit your order to advance the game yet. Also for the reason Doushibag suggests.
I've also been wanting something like this as a means for showing your teammates your orders without committing. Being able to save them without committing would serve that purpose really well.