I personally believe that the TellTale games and distribution system would work very well on Linux and Macintosh systems. A lot of adventure gamers use Macintosh or Linux and a lot of Macintosh and Linux users have broadband. I would venture to guess that the percentage of Macintosh and Linux users who have broadband is much higher than those who have Windows. Of course, more people have windows, but that doesn't mean that they are interested in buying and downloading adventure games. ScummVM.org has kind of laid a way for adventure games on Linux and Macintosh systems. There are also systems like Linspire's Click'N Run where someone can buy and download software with a single click. Some Linux users are even willing to pay triple the cost of a Windows version, for an older game. Just look at tuxgames.com(I'm not one of those, btw).
The rendering engines of the games, would of course, need to be ported from DirectX to Opengl and maybe a software renderer. The game might also need to use portable libraries such as SDL. However, if the engine of the games stays the same, then each subsequent game should be easy to port to Mac and Linux. Also, porting to Mac is often very similar to porting to Linux, if it's done right, which makes porting to both systems not much harder than porting to one.
There are some Linux enthusiasts who are more insterested in getting good games on Linux, than striking it rich. I do not know them personally, so I cannot speak for them, but I believe that to be true. Ryan Gordon of icculus.org is one good example, and he often maintains both Mac and Linux ports.http://www.linuxgamepublishing.com/ seems more interested in doing it right, than releasing games on time. There are others who have not quite been as successful, yet, because the lack the contracts, but are still very qualified. I know of a group that has a working port of Starcraft, but Blizzard is reluctant for various reasons.
If you would be interested in finding someone who would like to port the game/s I could find some people and e-mail them to see if they would also be interested and give them an e-mail address to contact.