I think they should make it a daily deal, but not for a week. They should also eat the discount cost, which they apparently aren't doing, and entirely waive their cut.

What I think they should do instead of extending the deal, is reset the games launch.

There is absolutdly no reason Valve couldn't re-launch the game, along with all the algoritm benefits an unbugged 1.0 launch should have had.

Also, you seem to have missed that the article says they are contractually obligated to complete their current WIP game. Valve giving them a bunch of money would not give them time to work on further updates for Planet Centauri before then.