Short answer: If the Kickstarter is successful, we'll have to wait and see if sales of the game will cover development costs for mobile development. If the Kickstarter is VERY successful, we would be able to consider those things from the start.
Longer answer: If the project does super well, porting the game to mobile platforms is an immediate priority after getting the base game developed on PC/Mac. Our development tool makes it easier to deploy games on mobile platforms (much more so than the original Auditorium), but there is a significant amount of time and expense involved in optimization, testing, and tweaking.
We want to make Auditorium Duet as good as it can be on the desktop, and be sure we can get the multiplayer experience down pat before we start experimenting on mobile platforms.