Just had to stop by and say a couple of things here...
Firstly, I welcome the thought of TellTale releasing their games on multiple platforms.
Secondly, in order to maximize the user base and minimize additional development cost for any ports, I submit the following suggestion:
Release the game on one disc, containing the data files and whichever platform engines TellTale wish to make themselves.
Then, release the source code of the engine only (obviously you do NOT want to use the GPL), or even just the bits and pieces required to be different between platforms, and let the fans do ports to whatever operating system they would like to see the game ported to. THEN, gather those engines on the TellTale website and put them up for download, so people who go out and buy the disc can download a suitable engine for whatever platform they currently use.
Of course, this requires that TellTale be utterly devoted to their fans, but in return they will surely gain a huge and completely loyal fanbase (relative to the number of adventure gamers across the world) and can use the ports as the basis of portable engines in the future, thereby cutting development cost on future titles while being able to release multiple engines on one disc.
Another sideeffect of releasing source code and portable engines will of course be that TellTale's games will outlast most every game on the market today, thanks to devoted fans and constantly updated engines and even new ports to as-of-yet non-existant operating systems and consoles.
I also hope TellTale will continue LucasArts' fine tradition of educating users on the importance of always installing and playing off of a backup in order to protect the original from damage. Being a collector who really cares about keeping my originals in mint condition WAY into the future, I owe a lot to LucasArts for showing me how a true collector works to maintain his collection.
In summary, I have high hopes for a bright future as TellTale works to bring adventure gaming back to its roots. LucasArts sure won't.